ENABLE PROGRAMME

(1)

ENABLE PROGRAMME MOLE CONCEPT

LAW OF CHEMICAL COMBINATION

1. Law of mass conservation (or Law of indestructibility) : It is given by Lavoisier and tested by

Landolt According to this law, the mass is not created or destroyed in a chemical reaction or

physical reaction. But one form is changed into another form is called as law of mass conservation.

If the reactant is completely converted in products.

Then the sum of the mass of reactants is equal to the sum of the mass of products.

.productsofmassTotalsttanreacofmassTotal =

If reactant are not completely consume then the relationship will be:

ttanreacunreactedofMassproductofmassTotalttanreacofmassTotal +=

Ex.

Special Note: The mass conservation law is not applicable in nuclear reactions.

2. Law of definite proportion (or Law of constant composition) : Given by Proust

According to this law, a compound is obtained from different sources. But the ratio of each

component (by weight) remain same i.e. it does not depend on the method of its preparation or the

source from which it has been obtained.

For example, molecule of ammonia always has the formula 3NH . That is one molecule of ammonia

always contains. One atom of nitrogen and three atoms of hydrogen or 17.0 g of 3NH always

contains 14.0 g of nitrogen and 3 g of hydrogen.

Ex. Water can obtain from different sources but the ratio of weight of H and O remain same.

Special Note: This law is not apply in isotopes.

HCl2ClH 22 →+

712 + )5.351(2 +

g73712 =+ g73

(2)

3. Law of multiple proportion: Given by → Daltons, According to law of Multiple proportion if two

elements combine to form more than one compound than the different mass of one element which

combine with a fixed mass of other element bear a simple ratio to one another.

Number of parts by weight of oxygen which combine with 14 parts by weight of nitrogen from the

above are 8, 16, 24, 32 and 40 respectively. Their ratio is 1 : 2 : 3 : 4 : 5, which is a simple ratio. Hence,

the law is illustrated.

Sulphur combines with oxygen from two oxides 2SO and 3SO , the weights of oxygen which

combine with a fixed weight of sulphur, i.e. 32 parts by weight of sulphur in two oxides are in the

ratio of 32 : 48 or 2 : 3 which is a simple ratio. Hence the law of multiple proportions is illustrated

4. Law of reciprocal proportion (or law of equivalent weight) : Given by → Richter.

The ratio of the weights of two elements A and B which combine separately with a fixed weight of

the third element C is either the same or some simple multiple of the ratio of the weights in which A

and B combine directly with each other.

This law is illustrated with the help of the following examples:

The elements C and O combine separately with the third element H to form 4CH and OH2 and

they combine directly with each other to form 2CO as shown in the adjoining figure. In 4CH , 12

parts by weight of carbon combine with 4 parts by weight of hydrogen. In OH2 , 2 parts by weight

of hydrogen combine with 16 parts by weights of oxygen. Thus the weights of C and O which

combine with fixed weight of hydrogen (say 4 parts of weight) are 12 and 32, i.e. they are in the ratio

12 : 32 or 3 : 8.

Now in 2CO , 12 parts by weight of carbon combine directly with 32 parts by weight of oxygen, i.e.

they combine directly in the ratio 12 : 32 or 3 : 8 which is the same as the first ratio.

5. Law of gaseous volume: Given by Gay Lussac.

According to this law, in the gaseous reaction, the reactants are always combined in a simple ratio

by volume and from products, which is simple ratio by volume at same temperature and pressure.

Ex. tryStoichiome211 ←

)g()g(2)g2( HCl2ClH →+

Volume2Volume1Volume1 +

One volume of hydrogen combines with one volume of chlorine to produce 2 volumes of hydrogen chloride.

Simple ratio = 1 : 1 : 2.

(3)

EXERCISE – 1

Molecular formula & empirical formula Basis Questions

1. In a compound x is 75.8% and y is 24.2% by weight present. If atomic weight of x and y are 24 and

16 respectively. Then calculate the empirical formula of the compound.

2. In a compound Carbon = 52.2%, Hydrogen = 13%, Oxygen = 34.8% are present and molecular mass

of the compound is 92. Calculate molecular formula of the compound?

3. A hydrocarbon contain 80%C. The vapour density of compound is 30. Molecular formula of

compound is:-

(a) 3CH (b) 62HC (c) 124HC (d) All of these

4. Two elements X (Atomic weight = 75) and Y (Atomic weight = 16) combine to give a compound

having 75.8% of X. The empirical formula of compound is:

(a) XY (b) YX2 (c) 22YX (d) 32YX

5. In a compound, A (Atomic weight = 12.5) is 25% and B (Atomic weight = 37.5) is 75% by weight. The

Empirical formula of the compound is:

(a) AB (b) BA2 (c) 22BA (d) 32BA

Significant Number

6. Give the number of significant figures in each of the measured numbers-

(a) 42.2 g (b) 3 eggs (c) 0.0005 cm (d) 450000 km.

(e) 9 Planets (f) 0.00035 g (g) 2000 m (h) 2.0045 L

(i) 5104 × g (j) 5100.4 × g (k) 51000.4 × g (l) 0.075 m

(m) 850000 m (n) 1250000 people (o) 41080.1 × g (p) C0.30 o

(q) 11.005 g (r) 31070.5 −× g

7. Why do measured numbers have a limited number of significant figures?

8. Write each of the following numbers in scientific notation with two significant figures-

(a) 5000 L (b) 30000 g (c) 100000 m

9. When are zeros in a measured number counted as significant figures? When are they not significant?

10. Write each of the following numbers in scientific notation with three significant figures:

(a) 5100000 (b) 2600 (c) 40000

11. Round off each of the following numbers to three significant figures:-

(a) 35.7823 m (b) 0.002627 L (c) 3826.8 g (d) 1.2836 kg

12. Perform the following calculations of measured numbers. Give the answers with the correct number of significant figures:-

(a) 37.08.56 × (b) 11

4.71 (c)

00.5

0.25 (d)

)0045.0()42.8(

)585.0()075.2(

13. Solve the following (considering significant figures).

(a) 01088.026.45 × (b) 2.6 / 324 (c) 16

00.80.4 ×

14. Solve the following (considering significant figures).

(a) 27.8 cm + 0.235 cm (b) 104 .45 ml + 0.838 ml + 46 ml

(c) 153.247 g – 14.82 g (d) 82.45 mg + 12.45 mg + 0.00056 mg

(e) 4.259 L – 3.8 L.

(4)

15. Why do we usually need to round off calculations that use measured numbers?

16. Round off each of the following numbers to three significant figures:

(a) 1.854 (b) 184.2038 (c) 0.004738265 (d) 8807 (e) 1.832149

17. Why do we sometimes add a zero to a member in a calculator display?

18. 3 g of a hydrocarbon on combustion in excess of oxygen produces 8.8 g 2CO and 5.4 g of OH2 . The

data illustrates the law of-

(a) Conservation of mass (b) Multiple proportion

(c) constant proportions (d) None of these

19. 1.80 g of a certain metal burnt in oxygen gave 3.0 g of its oxide 1.50 g of the same metal heated in

steam gave 2.50 g of its oxide. Show that these results illustrate the law of constant proportion.

20. Carbon is found to form two oxides which contain 42.9% and 27.3 % of carbon respectively. Show

that these figures illustrate the law of multiple proportions.

Mole Concept

# Mole is a unit of chemical substance.

# Mole ≡ mol ≡ gram molecule ≡ gram ion.

# Number of mole of particular atom = number of moleculeinatom particular × mole of molecule.

# Mole = weightMolecular

gmweight )(

# The weight of one mole compound is equal to its molecular weight.

# Mole of molecules / atoms / ions / p / n / e = AN

enpionsatomsmoleculesofNumber /////

# NA = Avogadro’s number = 6.023 × 1023.

# One mole molecules has 6.023×1023 molecules.

# Density of water = 1 gm/ml at C4o

# RT

PVn =

# Mole of gas = 22400

)ml(NTPatgasofVolume

litre4.22

.)lt(NTPatgasofvolume=

# Volume of one mole gas at STP is 22.4 litre.

# Mole = molarity × volume (lt.)

# Mole fraction of solute,

Nn

n

solventofMolessoluteofMoles

soluteofMolesXn

+=

+=

# Mole fraction of solvent,

Nn

N

solventofMolessoluteofMoles

solventofMolesXN

+=

+=

# The sum of mole fraction of components in a two component system is equal to unity i.e.,

1XX BA =+

# Avogadro’s Principle : State that under same conditions of temperature and pressure, equal volume

of gases contain the same number of molecules.

(5)

EXERCISE – 2

1. Calculate the number of molecules, atoms and protons in 32 gram CH4. 2. Calculate the total number of molecules in 32 gram molecule oxygen. 3. Calculate number of mole of H, O, and P in 5 mole H3PO4. 4. Calculate the weight of 12.046×1023 molecules of CaCO3. 5. Calculate the number of molecules in 44.8 litres of NO2 gas at NTP. 6. A piece of Ag weighs 0.108 gm. How many atoms of Ag does it contain ? 7. Calculate the volume of 8 gram of oxygen gas at NTP ? 8. From 400 mg of CO2, 1021 molecules are removed. How many moles of CO2 are left ? 9. Calculate the number of atoms present in 5.6 litre of a (i) monoatomic (ii) diatomic gas at NTP. 10. Calculate the number of atoms in 96 gm of ozone at NTP. 11. Calculate the number of oxygen atoms in 4 mole of FeSO4.7H2O. 12. Calculate total number of ions in

(a) 24 gram ion of N3-. (b) 24 gram of N3- ion. 13. Calculate total number of electrons in 9 gram water. 14. Calculate the number of electrons, protons and neutrons in 5 mole of O2- ions. 15. Calculate the mass of nitrogen contained in 1 kg of (i) KNO3 (ii) NH4NO3 and (iii) (NH4)2HPO4. 16. Calculate the total number of atoms in 0.5 mole of K2Cr2O7. 17. Calculate total charge in coulomb in

(a) 21 gram azide )N( 3

− ion. (b) 42 gram ion of N3.

(c) 27 gram of Al3+ ions (d) 2 gram ion of N3- 18. Calculate the ratio of the number of molecules contained in 1 gram of NH3 and 1 gram of N2 19. If the concentration of a solution is 4 M. Calculate the number of moles present in 200 ml of the

solution. 20. How many moles of any gas present in 1 meter3 at NTP ? 21. Calculate the weight in grams of oxygen in 0.1 mole of washing soda. 22. Equal masses of oxygen, hydrogen and CH4 are taken in a container in identical condition. What is

the ratio of the volumes of the gases ? 23. What is the volume of H2O when 22.4 litre water vapour condensed at 40C ? 24. The weight of 350 ml of a diatomic gas at 00C and 2 atm pressure is 1 gram. What is weight of one

atom ? 25. Calculate weight of one atom of carbon ? 26. 600 ml of a mixture of O3 and O2 weight 1 gm at NTP. Calculate volume of O3 in mixture. 27. How many mole of electrons weigh one kilogram ?

28. Naturally occurring chlorine is 75.53% 35Cl which has an atomic mass of 34.969 amu and 24.47% 37Cl , which has a mass of 36.969 amu. Calculate the average atomic mass of chlorine

29. Calculate the mass in g of

(a) 2 g-atom of Mg (b) 3 AN atoms of Mg

30. How many molecules are in 5.23 g of glucose ?)OHC( 6126 Also calculate the number of C, H and O

atoms. 31. What is the molecular weight of a substance, each molecule of which contains 9 carbon atoms, 13

hydrogen atoms and 231033.2 −× g of other component?

32. What is the weight of 231001.3 × molecules of ammonia? 33. How many years it would take to spend Avogadro’s number of rupees at the rate of 1 million rupees

in one second? 34. How many g of S are required to produce 10 moles and 10g of 42SOH respectively?

35. From 280 mg of CO, 2110 molecules are removed. How many g and mole of CO are left? 36. Calculate the number of molecules in a drop of water weighing 0.09g. 37. A compound contains 25% hydrogen and 75% carbon by mass. Determine the empirical formula of

the compound. 38. The mass and charge of 1 mol electrons will be

(a) 1kg; 96500C (b) 0.55 mg; 96500C (c) 1.55 mg; 96500C (d) 5.5mg; 96500C

(6)

39. Which of the following statements is incorrect?

(a) One gram mol of silver equals g10023.6

108 23×

(b) One mole of 4CH and 17g of 3NH at N.T.P. occupy same volume

(c) One mole Ag weighs more than that of two moles of Ca

(d) One gram mole of 2CO is 2310023.6 × times heavier than one molecule of 2CO

40. One atom of an element X weighs 2310664.6 −× g. The number of gram atoms in 40 kg of it is

(a) 10 (b) 100 (c) 10000 (d) 1000 41. 26.8g of OnH.SONa 242 contains 12.6 g of water. the value of ‘n’ is

(a) 1 (b) 10 (c) 6 (d) 7.

42. The mass of carbon present in 0.5 mol of ])CN(Fe[K 64 is

(a) 1.8g (b) 18g (c) 3.6 g (d) 36g 43. Which of the following has smallest number of molecules

(a) 11.2 L of 2O at NTP (b) 8 g of 2O

(c) 0.1 mole of 2O (d) mL1024.2 4× of 2O at STP

44. The largest number of molecules is in : (a) 28 g of CO (b) 46 g of OHHC 52 (c) g36 of OH 2 (d) g54 of 52 ON

45. 22106.4 × atoms of an element weight 13.8 g. The atomic mass of the element is : (a) 290 (b) 180 (c) 34.4 (d) 10.4 46. The total number of protons in 10 g of calcium carbonate is :

(a) 24100115.3 × (b) 24105057.1 × (c) 24100478.2 × (d) 24100956.4 × 47. How many molecules are present in one mL of water vapours of STP?

48. Calculate the number of −Cl and +2Ca ions in 333 g anhydrous 2CaCl .

49. The ratio of volumes occupied by 1 mol 2O and 1 mol 2CO under identical conditions of

temperature and pressure is (a) 1:1 (b) 1:2 (c) 1:3 (d) 2:1

Density

# Density of air is 0.00129 gm/ml. Density

Absolute density Relative density

Density= Mass

Volume

Vapour densitySpecific gravity Specific gravity : density of chemical substance with respect to density of water at similar condition, is called sp. gravity.

Sp. gr. = waterofdensity

cesubschemicalofdensity tan

density of water = 1 gram/ml. So Sp. gr. = density of chemical substance

Vapour density : The density of gas with respect to hydrogen at similar condition, is called as vapour density of gas.

V. D. = NTPatHydrogenofDensity

NTPatgasofDensity =

4.22/2

4.22/wtmolecular

V.D. = 2

wtmolecular

(7)

EXERCISE – 3

1. What is the density of oxygen with respect to air?

2. What is the density of chlorine with respect to air ?

3. Density of air is 0.001293 gm/cc. What is its vapour density ?

4. The density of O2 at NTP is 1.429 gm/L. Calculate standard molar volume of the gas.

5. The measured density of He at NTP is 0.1784 gm/L. What is the weight of 1 mole of it ?

6. The vapour density of a mixture consisting of NO2 and N2O4 is 38.3 at 26.70C. Calculate the number

of moles of NO2 in 100 gm of the mixture.

7. A nugget of gold and quartz weighs 100 gm. Sp. gr. of gold, quartz and nugget are 19.3, 2.6 and 6.4

respectively. Calculate the weight of gold in the nugget.

8. How many litre of liquid CCl4 (d = 1.5 gm/cc) must be measured out to contain 1×1025 CCl4

molecules ?

9. The vapour density of a mixture consisting of NO2 and N2O4 is 38.3 at 26.70C. Calculate the number

of mole of NO2 in 100 mole of the mixture.

10. Assuming that molecular formula of petrol is C8H18 and has density 0.8 gm/ml. What mole of

oxygen will consumed on complete combustion of 1.425 litre of petrol ?

11. The density of a liquid is 1.2 g/mL. There are 35 drops in 2 mL. The number of molecules in 1 drop

is (molecular weight of liquid =70)

(a) AN35

2.1 (b) A

2

N35

1

(c) A2

N)35(

2.1 (d) 1.2 AN

12. 40%(w/v) of NaCl solution (specific gravity=1.12) is equivalent to

(a) 51057.3 × ppm (b) ppm1057.3 6× (c) ppm101 6

× (d) ppm104 5×

13. What volume of a liquid will contain 4 mole ? Molar mass of liquid is 280 and its density is

1.4 g /mL.

(a) 0.4 L (b) 1.6 L (c) 0.8 L (d) L108.4 23×

(8)

Principle of Atom Conservation (POAC) & Eudiometry Or Gas Analysis

# It is the principle of conservation of mass.

# It expressed in the concept of atomic theory, means conservation of atoms. If atoms are

conserved, mole of atoms are also be conserved. This is why it is called as principle of atom

conservation.

e.g. )(2)(3 )( qs OKClKClOs

+→

Applying POAC for K.

Mole of K atom of reactant = mole of K atom of product.

1 × mole of KClO3 = 1 × mole of KCl

1× KClofwtMolecular

KClofwt

wtMolecular

KClOofwt×= 13

Applying POAC for Cl atom.

Mole of Cl atom of reactant = mole of Cl atom of product

1 × mole of KClO3 = 1× mole of KCl.

Applying POAC for O atom

Mole of O atom of reactant = mole of Oxygen atom of product

3 × mole of KClO3 = 2 × mole of O2

4.22

23 23 NTPatOofvolume

wtmolecular

KClOofwt×=×

# Eudiometer ⇒ Volume of gas measurement in ml.

# Different gases are absorbed by suitable reagent-

KOHSO&CO 22 ⇒

⇒2O Alkaline Pyrogallol

CO ⇒ Ammonical Cuprous chloride

Water vapour ⇒ liquid on cooling (Volume of water is neglected)

3O is absorbed by turpentine

(9)

EXERCISE – 4

1. A sample of KClO3 on decomposition yielded 448 ml of oxygen gas at NTP. Calculate

(i) weight of oxygen produced.

(ii) weight of KClO3 originally taken

(iii) weight of KCl produced.

2. 27.6 gram of K2CO3 was treated by a series of reagents. So as to convert all of

its carbon to K2Zn3 (Fe(CN)6)2 of molecular weight 698. Calculate the weight of product.

3. Value of ‘n’ and weight of polyethene obtained in following reaction by 24 kg carbon atoms?

4. Volume of )g(3)g(2 OandO obtained by 8 kg oxygen atoms at STP?

5. Mole of )g(3SO obtained by 640 g sulphur atoms at STP?

6. Weight of 104OP obtained 620 g phosphorus atoms ?

7. Volume of )g(62)g(4 HCandCH obtained by 6 kg carbon atoms at STP?

8. Moles of benzene obtained by 600 g C-atoms?

9. Weight of )g(2CO obtained by complete combustion of 480 g carbon atoms?

10. Volume of )g(CO at STP obtained by 8 kg of oxygen atoms?

11. Weight of carbon atoms required to prepare 36 kg benzene?

12. Weight of oxygen atom required to prepare 196 kg 42SOH ?

13. 20 ml of CO was mixed with 50 ml of oxygen and the mixture was exploded on cooling, the

resulting mixture was shaken with KOH. Find the volume of gas that is left

14. What volume of oxygen will be required for the complete combustion of 18.2 litres of propane at

NTP?

15. 10 mL of a gaseous hydrocarbon was burnt completely in 80 mL of 2O at NTP. The remaining gas

occupied 70 mL at NTP. This volume became 50 mL on treatment with KOH solution. What is the

formula of the hydrocarbon?

16. A sample of a gaseous hydrocarbon occupying 1.12 litres at NTP when completely burnt in air

produced 2.2 g of 2CO and 1.8 g of OH2 . Calculate the weight of the compound taken and the

volume of 2O at NTP required for its burning. Find the molecular formula of the hydrocarbon.

17. 7.5 mL of a hydrocarbon gas was exploded with excess of oxygen. On cooling, it was found to have

undergone a contraction of 15 mL. If the vapour density of the hydrocarbon is 14, determine its

molecular formula.

18. A 40-mL sample of a mixture of 2H and 2O was placed in a gas burette at C18o and 1 atm pressure.

A spark was applied so that the formation of OH2 was complete. The remaining pure gas had a

volume of 10 mL at C18o and 1 atm pressure. If the remaining gas was hydrogen, what was the

initial mole percent of hydrogen in the mixture?

19. 60 mL of a mixture of nitrous oxide and nitric oxide was exploded with excess of hydrogen. If 38 mL

of 2N was formed, calculate the volume of each gas in the mixture.

(10)

20. A mixture of formic acid and oxalic acid is heated with concentrated 42SOH . The gas produced is

collected and on its treatment with KOH solution the volume of the gas decreased by one-sixth.

Calculate the molar ratio of the two acids in the original mixture.

21. Calculate the volume of 2CO produced by the combustion of 40 mL of acetone in the presence of

excess of oxygen.

22. What volume of air will be required to oxidise 210 mL of sulphur dioxide to sulphur trioxide, if the

air contains 21% of oxygen?

23. What volume of 2CO is obtained in the combustion of 2 litres of butane?

24. If a mixture containing 12 litres of hydrogen and 11.2 litres of chlorine is exploded in an eudiometer

tube, what will be the composition of the resulting mixture by volume?

25. What volume of oxygen is required for complete combustion of 2.2 g of propane at NTP?

26. 500 mL of a hydrocarbon gas, burnt in excess of oxygen, yields 2500 mL of 2CO and 3 litres of water

vapour, all volumes being measured at the same temperature and pressure. What is the formula of

the hydrocarbon?

27. When 0.02 litre of a mixture of hydrogen and oxygen was exploded, 0.003 litre of oxygen remained.

Calculate the initial composition of the mixture in percent by volume.

28. 12 mL of a gaseous hydrocarbon was exploded with 50 mL of oxygen. The volume measured after

explosion was 32 mL. After treatment with KOH the volume diminished to 8 mL. Determine the

formula of the hydrocarbon

29. 20 mL of a mixture of 22HC and CO was exploded with 30 mL of oxygen. The gases after the

reaction had a volume of 34 mL. On treatment with KOH, 8 mL of oxygen remained. Calculate the

composition of the mixture.

30. On passing 25 mL of a gaseous mixture of 2N and NO over heated copper, 20 mL of the gas

remained. Calculate the percentage of each in the mixture.

31. A mixture of 20 mL of CO, 4CH and 2N was burnt in an excess of oxygen, resulting in reduction of

13 mL of volume. The residual gas was treated with KOH solution when there was a further

reduction of 14 mL in volume. Calculate the volumes of CO and 4CH in the given mixture

32. When 100 mL of an mixture was passed through turpentine, there was reduction of volume by 20

mL. If 100 mL of such a mixture is heated, what will be the increase in volume?

Limiting Reagent (L.R.)

(11)

EXERCISE – 5

1. If 0.5 mol of 2BaCl is mixed with 0.2 mol of 43PONa , the maximum amount of 243 )PO(Ba that can

be formed is (a) 0.70 mol (b) 0.5 mol (c) 0.20 mol (d) 0.10 mol

2. Study the following table

Compound (mol. mass) Mass of the compound (in gram) taken

I. )44(CO2 4.4

II. 2NO (46) 2.3

III 22OH (34) 6.8

IV )64(SO2 1.6

Which two compounds have least mass of oxygen? (Molecular masses of compounds are given in brackets)

(a) II and IV (b) I and III (c) I and II (d) III and IV

3. The phosphate of a certain metal M is 243 )PO(M . The correct formula of metal sulphate

would be

(a) 342 )SO(M (b) 4MSO (c) 243 )SO(M (d) 42SOM

4. The percentage of Se in peroxidase enzyme is 0.5% by mass (atomic mass of Se=78.4amu). Then, the minimum molecular mass of enzyme which contains not more than one Se atom is

(a) amu10568.1 4× (b) amu10568.1 7

× (c) amu10568.1 3× (d) 610568.1 × amu

5. The maximum amount of 4BaSO that can be obtained on mixing 0.5 mol 2BaCl with 1 mol 42SOH

is (a) 0.5 mol (b) 0.1 mol (c) 0.15 mol (d) 0.2 mol

6. The molar mass of ON2 as well as 2CO is 44 1molg − . At 25°C and 1 atm pressure, 1L ON2

contains n molecules of gas. The number of 2CO molecules in 2L under same conditions will be

(a) n (b) 2n (c) 2

n (d)

4

n

7. 5.85 g NaCl is dissolved in 1L water. The number of ions of +Na and −Cl in 1 mL of this solution will be

(a) 191002.6 × (b) 22102.1 × (c) 20102.1 × (d) 201002.6 ×

8. Phosphine )PH( 3 decomposes to produce vapours of phosphorus and 2H gas. What will be the

change in volume when 100 mL of phosphine is decomposed? (a) +50 mL (b) +500 mL (c) +75 mL (d) –500mL

9. The density of a liquid is 1.2 g/mL. There are 35 drops in 2 mL. The number of molecules in 1 drop is (molecular weight of liquid =70)

(a) AN35

2.1 (b) A

2

N35

1

(c) A2

N)35(

2.1 (d) 1.2 AN

10. In the reaction, ,CBAC3B2A4 324→++ what will be the number of moles of product formed,

starting from 1 mol of A, 0.6 mol of B and 0.72 mol of C? (a) 0.25 (b) 0.3 (c) 0.24 (d) 2.32

11. 26.8g of OnH.SONa 242 contains 12.6 g of water. the value of ‘n’ is

(a) 1 (b) 10 (c) 6 (d) 7. 12. Consider the following data

Element Atomic weight A 12.01 B 35.5 A and B combine to form new substance X. If 4 mol of B combine with 1 mol of A to give 1 mol of X, then the weight of 1 mol of X is. (a) 154 g (b) 74g (c) 47.5g (d) 160g

(12)

Percentage and concentration of solution

% of weight by weight or (% w/w) = 100gmin solution ofwt

gmin solute of wt×

% of weight by volume or (% w/v) = 100mlin solution of volume

gmin solute of wt×

% of volume by volume or (% v/v) = 100mlin solution of volume

mlin solute of olumev×

Parts per million (PPM) = 610solution ofAmount

solute of Amount×

(100 + x%) of oleum means x gram OH2 reacts with free 3SO to give 42SOH

Degree of Hardness

� It is defined as the number of part by weight of 3CaCO present per million parts by weight of

water. � Degree of hardness is measured in parts per million (ppm)

� Degree of hardness (in ppm) = 63 10waterofweight

CaCOofpartof.no×

Concentration Represents in terms of – * Molarity * Molality * Normality

Molarity : The number of mole of solute present in one litre solution is called Molarity.

Molarity (M) = litrein solution of volumewt molecular

gm.in solute of weight

lt.in solution of volume

solute of mole

×=

Unit- mole/litre Molality (m): The number of mole of solute present in one kilogram of solvent is called molality.

Molality (m) = kg.in solvent ofwt

solute of mole

Unit – mole / kilogram # Molality, mole fraction, % by wt. are temperature independent. # Moles, milli-moles, equivalent, milli-equivalent of solute does not change on dilution.

Normality (N): The number of gram equivalent of solute present in one litre solution is called as normality.

Normality (N) = litrein solution of Volume

solute of equivalent gram ofNumber

Unit - gram equivalent / litre.

Number of gram equivalent = wt.Equivalent

(gm.) solute of wt

Equivalent Weight :

eg. Equivalent of Na in 222 ONa and ONa

(13)

O

OO

ONa

NaNa

Na

2

22

2

∵ 16 gram O reacts with 46 gm of Na

∴ 8 gram O reacts = Na ofgm816

46 ×

Equivalent of Na in 23ONa2 =

2

22

22

22

2

O

OO

ONa

NaNa

Na ∵ 32 gm O reacts with 46 gm of Na

∴ 8 gm O reacts = 11.5832

46=×

Equivalent wt of sodium in 22ONa = 11.5

# Equivalent wt of Element = valency

wtAtomic

# Equivalent wt of acid = basicity

wtmolecular

Basicity

3POH 43 → 2POH 33 → 1POH 23 → 2SOH 42 →

1HNO3 →

# Equivalent wt of base = acidity

wtmolecular

Acidity

NaOH → 1 KOH → 1 2)OH(Ca → 2 3)OH(Al 3 →

# Equivalent wt of salt = or anion on cationeargch

wtmolecular

eg. −−+++→ 33 COCaCaCO

=3CO wt of Caequivalent 502

100=

# Equivalent of some metal compound if metal has equivalent E.

Metal chloride = E + 35.5 Metal oxide = E + 8

Metal hydroxide = E + 17 Metal carbonate = E + 30

# Equivalent wt of compound in redox reaction = numberoxidation change in

wtmolecular

eg.

4321

5

5

2

2

32

32

MMMMwtmolecular if

OVOFeOFeOV++++

+→+

Equivalent wt of VO = 3

M

25

M 11 =−

Equivalent wt of 2

M

46

MOFe 22

33 =−

=

Equivalent wt of 1

M

12

MFeO 33 =

−= Equivalent wt of

6

M

410

MOV 44

52 =−

=

Milliequivalent:-

Number of millequivalent = 1000wtEquivalent

)gm(soluteofWeight×

= Normality × volume (ml)

= 1000volumeEquivalent

gasofVolume×

D4C3B2A +→+

Equivalent of A = Equivalent of B = Equivalent of C = Equivalent D

Milliequivalent of A = Milliequivalent of B = Milliequivalent of C = Milliequivalent of D

(14)

EXERCISE – 6

1. Equivalent wt of following chemical species.

N, O, 42SOH , HCl, 3HNO , 43POH , 33POH , 23POH , NaOH, 2)OH(Ca , 3)OH(Al , NaCl, 42SONa

2. Equivalent wt of 4KMnO

(a) in acidic medium

(b) in basic medium

(c) in neutral medium.

3. In the reaction −−−+→+ I2OSIOS2 2

642232 . What is the equivalent weight of 322 OSNa ?

4. In the reaction NaClNaHCOHClCONa 332 +→+ . What is equivalent weight of 32CONa ?

5. What is equivalent weight of 42CrOK acts as oxidizing agent in acidic medium?

6. 2 gram of base whose equivalent weight is 40 reacts with 3 gram of an acid. What is equivalent of

an acid.

7. 0.126 gram of an acid requires 20 ml of 0.1 N NaOH for complete neutralization. What is the

equivalent weight of acid?

8. 24 gram of an element combines with 16 gram of oxygen. What is the equivalent of the element?

9. What are equivalent volumes of Hydrogen, Oxygen and Nitrogen.

10. Calculate the number of equivalents in one mole of oxygen molecules

11. Calculate the volume at STP occupied by

(i) 0.1 mol of 2CO (ii) 6.023 × 2310 molecule of 3NH

(iii) 1 gm eq. of 2H (iv) 1 gm eq. of 2O

12. The wt. of 350 ml of a diatomic gas at C0o and 2 atm pressure is 1 gm. Calculate the weight in gm

of one atom

13. 1 gm of a metal in which specific heat of 0.06 combined with 2O to form 1.08 gm of its oxide. What

is the atomic mass of metal ?

14. A mixture of 1.65 × 2110 molecule of X and 1.85 × 2110 molecules of Y weighs 0.688 gm. If the

molecular mass of Y is 187. What is the molecular mass of X ?

15. The equivalent wt of metal is 29.73 and V.D of its chloride is 130.4. Find out the atomic mass of the

metal.

16. One atom of A weighs 23106 −× gm taking Av. No = 23106 × . What is the no. of gm atoms in 36 kg ?

17. Two elements A & B form two components 232 AB&BA such that if 0.15 mol of each weights 16.5

gm and 9 gm respectively. What is atomic wt of A & B ?

18. 4 gm mineral consists of equimolar quantities of the carbonate of two bivalent metals on heating

gives 2.2 gm 2CO . If mass % of one metal is 10%. What is the mass % of other metal?

19. On heating 3.98 gm of a metallic oxide in a current of hydrogen 0.9 gm of water was formed. What

is the equivalent wt. of metal?

(15)

20. 2.47 gm of CuO were obtained by oxidizing 1.986 gm of Cu by 3HNO . 0.335 gm of Cu were

precipitated by 0.346 gm of Zn from 4CuSO solution. What is the equivalent wt. of Zn?

21. If W gm of an insoluble silver salt of the carboxylic acid heated gently to leave behind a metallic

silver residue of mass 1w gm. What is equivalent wt. of acid ?

22. If 1.520 gm of the hydroxide of a metal gives 0.995 gm of it oxide. What is the equivalent wt. of

metal?

23. A gaseous compound of C & N containing 53.8 % by wt of N was found to have V.D of 25.8. What

is the molecular formula of compound?

24. Oxide of an element contain 67.67% of 2O and vapour density of its chloride is 79. What is the

atomic wt. of the element?

25. Density of a 16% (by mass) solution of 42SOH is 1.1094 g/mL. Calculate molality, molarity and

normality of solution .

26. How many gram of Sodium carbonate should be dissolved in water in order to prepare 500 mL

solution of 0.01 M concentration?

27. 20.6 g NaBr is dissolved in 500 mL solution. What is the molarity of resulting solution ?

28. 2.8 g nitrogen is dissolved in 500 mL solution. Calculate the molar concentration of nitrogen in the

solution .

29. Density of 2.03 M aqueous solution of acetic acid is 1.017 g/mL. Molecular mass of acetic acid is

60. Calculate the molality of solution .

30. 500 mL of a solution contains 1/10th of equivalent mass of HCl. Calculate the normality of solution.

31. 5.8 g acetone is dissolved in 450 g water, Calculate mole fraction of acetone and water in the

solution.

32. Calculate molality of the solution obtained by dissolving 11.7 g NaCl in 500 g water.

33. 149 gm of potassium chloride (KCl) is dissolved in 10 ltr. of an aqueous solution. Determine the

molarity of the solution (K = 39, Cl = 35.5)

34. 117 gm NaCl is dissolved in 500 mL aqueous solution. Find the molarity of the solution.

35. 225 gm of an aqueous solution contains 5 gm of urea. What is the concentration of the solution in

terms of molality. (Mol. wt. of urea = 60)

36. 518 gm of an aqueous solution contains 18 gm of glucose (mol. wt. =180). What is the molality of

the solution.

37. 0.5 g of a substance is dissolved in 25 g of a solvent. Calculate the percentage amount of the

substance in the solution.

38. 20 3cm of an alcohol is dissolved in 80 3cm of water. Calculate the percentage of alcohol in

solution.

39. Mass of KOH needed to prepare 100 ml 1 M KOH solution

40. Find the −Cl concentration in solution which is obtained by mixing one mole each of 2BaCl , NaCl

and HCl in 500 ml water

41. Find the mass of solute and solvent in 100 ml 1 M NaOH solution having density 1.5g/ml.

(16)

42. 3.0 litre of water are added to 2.0 litre of 5 M HCl. What is the molarity of HCl in the resultant

solution.

43. 224 ml of 2CO at N.T.P. is passed through 100 ml of 0.2 M solution of NaOH. What is the weight

of 32CONa formed.

44. Calculate the amount of 95% pure 32CONa molarity required to prepare 5 litre of 0.5 M solution.

45. 100 g of 3CaCO is treated with 500 ml M/2 solution of HCl. Find out the volume of 2CO evolved

at S.T.P. Which substance is limiting reagent .

46. 5g of 42SOK were dissolved in 250 ml of solution. How many ml of this solution should be used so

that 2.33 g of 4BaSO may be precipitated from 2BaCl solution.

47. (i) If you are given a 2M NaOH solution having density 1 gm/ml. Then write the molality of

solution .

(ii) Find the molarity of 5m (molal) NaOH solution having density 1.5 gm/ml

(iii) Find the mole fraction of solute in problem (i)

(iv) Find the mole fraction of solute in problem (ii)

(v) Find the % (w/w) of NaOH in solution in problem (i)

(vi) Find the % (w/w) of NaOH in solution in problem (ii)

(vii) Find the % (w/v) of NaOH in solution in problem (ii)

(viii) A 300 gm, 30% (w/w) NaOH solution is mixed with 500 gm 40% (w/w) NaOH solution.

Find the mass percentage (w/w) of final solution

(ix) What is % (w/v) NaOH in problem (viii) if density of final solution is 2 gm/ml.

(x) What is the molality of final solution obtained in problem, (viii)

48. A sodium hydroxide solution containing 40% by weight of pure NaOH has a specific gravity of

1.5. What volume of this solution will be required in the preparation of 500 mL of a 0.45 M NaOH

solution.

49. A silver coin weighing 20 g was dissolved in 3HNO and then further treated with HCl solution in

excess. The weight of AgCl formed in 14.35 g. What is the percentage of Ag in silver coin.

50. A gaseous alkane is exploded with oxygen. The moles of 2O for complete combustion and

2CO formed is in the ratio 7 : 4 . Deduce molecular formula of alkane .

51. 1000 ml of oxygen at NTP were passed through Siemens ozoniser when the resulting volume was

888 ml at NTP. This quantity of ozonized oxygen is passed through excess of potassium iodide

solution. Calculate weight of iodine liberated .

2O3 3O2

2232 OIKOH2OOHKI2 ++→++

52. Find the vapour density of a mixture containing an equal number of moles of methane and ethane

at STP.

53. Three oxides of nitrogen 22 NO,ON and 32ON are mixed in a molar ratio of 3 : 2 : 1. Find the

vapour density of gaseous mixture

(17)

54. The density of a solution containing 13% by mass of sulphuric acid is 1.09 g/mL. Calculate the

molarity of the solution.

55. The mole fraction of OHCH3 in an aqueous solution is 0.02 and its density is 0.994 g 3cm− .

Determine its molarity and molality.

56. The density of a solution containing 40% by mass of HCl is 1.2 g/ml. Calculate the molarity of the

solution :

57. 15 g of methyl alcohol is present in 100 mL of solution. If density of solution is 0.90 g 1ml− .

Calculate the mass percentage of methyl alcohol in solution.

58. What volume of 96% 42SOH solution (density 1.83 g/mL) is required to prepare 4 litres of 3.0 M

42SOH , solution ?

59. A 6.90 M solution of KOH in water contains 30% by mass of KOH. Calculate the density of the

solution.

60. Find the molarity of pure water at C40 when its density is 1g. 1ml− .

61. 105 ml of pure water at C40 saturated with 3NH gas yielded a solution of density 0.9g/ml. and

containing 30% 3NH by mass. Find the volume of resulting 3NH solution.

62. 50 ml of a water sample required 10ml of M/50 HCl for complete neutralization. Calculate the

temporary hardness of water in ppm.

63. What is the percent free 3SO in an oleum (considered as a solution of 3SO in 42SOH ) that is

labeled “109% 42SOH ”?

64. A solution contains 25% water, 50% ethanoic acid and 25% ethanol by mass. Compute the mole

fraction of each component .

65. In what ratio should you mix 0.2M 3NaNO and 0.1 M 23 )NO(Ca solution so that in resulting

solution the concentration of negative ions is 50% greater than the concentration of positive ions ?

66. (a) 12% solution of urea by weight is diluted by adding to it 7% urea solution by weight. In what

weight ratio should the solutions be mixed to get a 9% solution by weight ?

(b) In what ratio should a 6.5 N 3HNO will be diluted with water to get 3.5 N 3HNO ?

67. How many kilograms of wet NaOH containing 10% water are required to prepare 60 litres of a

0.5M solution ?

68. A litre of milk weighs 1.032 kg. The butter fat it contains to the extent of 4.0% by volume has a

density of 865 kg/m3. What is the density of the fat free “skimmed milk”.

69. Calculate the weight of CaO required to remove the hardness of 610 litre of water containing 1.62 gram of

23 )HCO(Ca per litre.

70. One litre of sample of hard water contains 1 mg of 2CaCl and 1 mg of 2MgCl . Find the total hardness of

water in terms of 3CaCO per 610 parts of water by weight.

71. 100 ml sample of hard water is passed through a column of the ions exchange resin 2RH . The water coming

off the column requires 15.17 ml of 0.0265 m NaOH for its titration. What is hardness of water in ppm of

++Ca ?

(18)

Level Level Level Level –––– I (JEEI (JEEI (JEEI (JEE----Main & NEET)Main & NEET)Main & NEET)Main & NEET)

1. What is the mass of one molecule of yellow phosphorus? [MHT CET]

(a) mg10993.1 22−× (b) mg10993.1 19−

× (c) mg10983.4 20−× (d) mg10983.4 23−

×

2. Which one of the following data has only four significant figures? [Kerala CEE]

(a) 2310023.6 × (b) 285 cm (c) 0.0025 L (d) 0.200 g

3. The system that contains the maximum number of atoms is [WB JEE]

(a) 4.25 g of 3NH (b) 8 g of 2O (c) 2 g of 2H (d) 4 g of He

4. 2110 molecule are removed from 200 mg of 2CO . The moles of 2CO left are [AIIMS]

(a) 31088.2 −× (b) 3108.28 −

× (c) 310288 −× (d) 3108.28 ×

5. One mole of 4CH contains [UP CPMT]

(a) 4 g atoms of hydrogen (b) 3.0 g atoms of carbon

(c) 231002.6 × atoms of hydrogen (d) 231081.1 × molecules of 4CH

6. The oxygen obtained from 72 kg of water is [UP CPMT]

(a) 72 kg (b) 46 kg (c) 50 kg (d) 64 kg

7. The weight of 112 mL of oxygen at NTP is [Manipal]

(a) 0.64 g (b) 0.96 g (c) 0.32 g (d) 0.16 g

8. For 14 g of CO, the wrong statement is [Manipal]

(a) it occupies 2.24 L at NTP

(b) it corresponds to 2

1 mole of CO

(c) it corresponds to same mole of CO and nitrogen gas

(d) it corresponds to 231001.3 × molecules of CO

9. The vapour density of a gas is 11.2. The volume occupied by one gram of the gas at STP is

[Manipal]

(a) 1.0 L (b) 11.2 L (c) 22.4 L (d) None of these

10. What is the atomic weight of an element X for which a sample containing 221058.1 × atoms weigh

1.05 g? [WB JEE]

(a) 28 g (b) 20 g (c) 40 g (d) 23 g

11. The percentage of 2N in urea is about [KCET]

(a) 28 (b) 18 (c) 85 (d) 46

12. Number of molecules in 1 L of water is close to [KCET]

(a) 23104.22

18× (b) 2310023.65.55 ×× (c) 2310

4.23

023.6× (d) 2310023.618 ××

(19)

13. The mass of 112 3cm of 4CH gas at STP is [KCET]

(a) 0.16 g (c) 0.8 g (c) 0.08 g (d) 1.6 g

14. How many moles of magnesium phosphate, 243 )PO(Mg will contain 0.25 mole of oxygen atom?

[AFMC]

(a) 0.02 (b) 210125.3 −× (c) 21025.1 −

× (d) 2105.2 −×

15. The number of sodium atom in 2 moles of sodium ferrocyanide is [Manipal]

(a) 231012 × (b) 231026 × (c) 231034× (d) 231048×

16. How many milliliters of a 42SOH N 9 solution will be required to neutralize completely 20 mL of a

36 N NaOH solution ?

(a) 18.0 mL (b) 9.0 mL (c) 16.0 mL (d) 80.0 mL

17. How many milliliters of a 42SOH N .10 solution will be required for complete reaction with a

solution containing 0.125 g of pure 32CONa ?

(a) 23.6 mL (b) 25.6 mL (c) 26.3 mL (d) 32.6 mL

18. 25.50 mL of an 42SOH solution reacted completely with 1.96 g of pure .CONa 32 What was the

normality of the acid solution ?

(a) 2.45 N (b) 1.54 N (c) 1.35 N (d) 1.45 N

19. A dilute solution of 42SOH is made by adding 5 mL of 36 42SOH N to 245 mL of water. The

normality and molarity of the solution are

(a) 0.70 N and 0.35 M (b) 0.35 N and 0.70 M (c) 0.35 N and 0.35 M (d) 0.70 N and 0.70 M

20. What volume of 42SONH is equivalent to 32.8 mL of 0.1452 42SOH N ?

(a) 4.05 mL (b) 4.80 mL (c) 8.40 mL (d) 9.60 mL

21. What volume of 0.5 M ( )2OHBa solution will react completely with 25 mL of 43POH N 3 ?

(a) 50 mL (b) 57 mL (c) 60 mL (d) 75 mL

22. The volume of 1.5 43POH M solution required to neutralize exactly 90 mL of a 0.5 ( )2OHBa M

solution is

(a) 10 mL (b) 30 mL (c) 20 mL (d) 60 mL

23. Calculate the weight of the 2BaCl needed for complete precipitation of 4BaSO from 30.5 mL of

.SOH N 1.0 42

(a) 0.32 g (b) 0.032 g (c) 3.2 g (d) 0.42 g

24. A sample of 1.0 g of calcite )CaCO Pure( 3 required 39.5 mL of HCl for complete reaction. Calculate

the normality of the acid.

(a) 0.41 N (b) 0.61 N (c) 0.51 N (d) 0.15 N

(20)

25. An excess of NaOH was added to 100 mL of a ferric chloride solution. This caused the

precipitation of 1.425 g of ( ) .OHFe 3 Calculate the normality of the ferric chloride solution.

(a) 0.20 N (b) 0.50 N (c) 0.25 N (d) 0.40 N

26. What volume of hydrogen sulphide gas (at STP) is required to precipitate completely the +2Pb ions

from 100 mL of a ( )23COOCHPb N 2.0 solution ?

(a) 112 mL (b) 224 mL (c) 448 mL (d) 22.4 mL

27. 200.0 mL of a 0.5 42SOH M solution contains

(a) 50 millimoles of 42SOH (b) 200 millimoles of 42SOH

(c) 100 millimoles of 42SOH (d) 10 millimoles of 42SOH

28. One mole of 42SOH will exactly neutralize

(a) 4 moles of an ammonia solution (b) 1 mole of ( )2OHBa

(c) 3 moles of ( )3OHAl (d) 0.5 mole of ( )2OHBa

29. A pure SOH 42 (98% by weight) solution has a specific gravity of 1.8. The normality of the 42SOH is

(a) 9 N (b) 18 N (c) 72 N (d) 36 N

30. The mass of oxalic acid crystals ( )OH2.OCH 2422 required to prepare 50 mL of a 0.2 N solution is

(a) 4.5 g (b) 6.3 g (c) 0.63 g (d) 0.45 g

31. The normality of a 1 M solution of 43POH is

(a) 0.5 N (b) 1.0 N (c) 3.0 N (d) 1.5 N

32. Hydrochloric acid solutions A and B have concentrations 0.5 N and 0.1 N respectively. The

volumes of solution A and solution B required to make a 2-litre solution of 0.2 N HCl are

(a) 0.5 L of A and 1.5 L of B (b) 1.5 L of A and 0.5 L of B

(c) 1.0 L of A and 1.0 L of B (d) 0.75 L of A and 1.25 L of B

33. The molarity of pure water is

(a) 5.55 mol/L (b) 18.0 mol/L (c) 55.55 mol/L (d) 10.0 mol/L

34. Calculate the volume of 0.1 42SOH N needed to precipitate all the +2Ba ions from 100 mL of a 0.01

2BaCl M solution.

(a) 40 mL (b) 20 mL (c) 80 mL (d) 10 mL

35. 50 mL of 5.6% KOH (w/v) is added to 50 mL of a 5.6% HCl (w/v) solution. The resulting solution

will be

(a) neutral (b) alkaline (c) strongly alkaline (d) acidic

36. 125 mL of 0.63% OHOCH 2422 2. is made to react with 125 mL of a 0.40% NaOH solution. The

resulting solution is

(a) neutral (b) acidic (c) strongly acidic (d) alkaline

(21)

37. 6 mL of a 0.5 N NaCl solution completely precipitates the AgCl from 20 mL of a 0.15 N

3AgNO solution. The amount of AgCl obtained in the reaction is (Ag = 108, Cl = 35.5)

(a) 0.429 g (b) 4.29 g (c) 0.0429 g (d) 1.429 g

38. 4.2 g of pure sodium bicarbonate is heated in air. The residue obtained is dissolved in water and

the volume is made up to 500 mL with water. The normality of the resulting solution is

(a) 0.05 N (b) 0.01 N (c) 0.25 N (d) 0.10 N

39. Calculate the molality of a sulphuric acid solution of specific gravity 1.2 containing 27% 42SOH by

weight.

(a) 8.4 (b) 3.3 (c) 0.38 (d) 3.8

40. 2.00 g of a mixture of 3NaHCO and 3KClO requires 100 mL of 0.1 N HCl for complete neutralization.

The weight of 3KClO present in the mixture is

(a) 0.84 g (b) 1.84 g (c) 1.16 g (d) 0.16 g

41. The normality of ’10-volume’ 22OH is approximately

(a) 17.8 N (b) 1.785 N (c) 5.00 N (d) 1.00 N

42. If 500 m ℓ of 1 M solution of glucose is mixed with 500 m ℓ of 1 M solution of glucose final

molarity of solution will be :

(a) 1 M (b) 0.5 M (c) 2 M (d) 1.5 M

43. The volume of water that must be added to a mixture of 250 ml of 0.6 M HCl and 750 ml of 0.2 M

HCl to obtain 0.25 M solution of HCl is :

(a) 0.75 ml (b) 100 ml (c) 200 m ℓ (d) 300 m ℓ

44. What volume of 0.10 M 42SOH must be added to 50 mL of a 0.10 M NaOH solution to make a

solution in which the molarity of the 42SOH is 0.050 M?

(a) 400 mL (b) 50 mL (c) 100 mL (d) 150 mL

45. What volume of 0.40 M 2)OH(Ba must be added to 50.0 mL of 0.30 M NaOH to get a solution in

which the molarity of the −OH ions is 0.50 M ?

(a) 33 mL (b) 66 mL (c) 133 mL (d) 100 mL

46. What volume of a 0.8 M solution contains 100 millimoles of the solute ?

(a) 100 mL (b)125 mL (c) 500 mL (d) 62.5 mL

47. 500 mL of a glucose solution contains 221002.6 × molecules. The concentration of the solution is .

(a) 0.1 M (b) 1.0 M (c) 0.2 M (d) 2.0 M

48. Mole fraction of A in OH2 is 0.2. The molality of A in OH2 is :

(a) 13.8 (b) 15.5 (c) 18.4 (d) 16.8

49. What is the molarity of 42SOH solution that has a density of 1.84 g/cc and contains 98% by mass of

42SOH . (Given atomic mass of S = 32)

(a) 4.18 M (b) 8.14 M (c) 18. 4 M (d) 18 M

50. The molality of a sulphuric acid solution is 0.2 mol/kg. Calculate the total weight of the solution.

(a) 1000 g (b) 1098.6 g (c) 980.4 g (d) 1019.6 g

(22)

Level Level Level Level –––– II (Old Year JEEII (Old Year JEEII (Old Year JEEII (Old Year JEE----Main & NEET)Main & NEET)Main & NEET)Main & NEET)

1. Assertion (A) Equivalent weight of a base is acidity

weightmolecular [AIIMS]

Reason (R) Acidity is the number of replaceable hydrogen atom in one molecule of the base.

(a) Both A and R are correct and R is the correct explanation of A

(b) Both A and R are correct but R is not the correct explanation of A

(c) A is correct but R is incorrect

(d) Both A and R are incorrect

2. The correctly reported answer of the addition of 4.523, 2.3 and 6.24 will have significant figures

[AFMC]

(a) two (b) three (c) four (d) five

3. The formula mass of Mohr’s salt is 392. The iron present in it is oxidized by 4KMnO in acidic

medium. The equivalent mass of Mohr’s salt is [AFMC]

(a) 392 (b) 31.6 (c) 278 (d) 156

4. A metal M of equivalent mass E forms an oxide of molecular formula yxOM . The atomic mass of

the metal is given by the correct equation [Kerala CEE]

(a) )x/y(E2 (b) xyE (c) E/y (d) y/E (e) )y/x(E2

5. Out of two oxides of iron, the first contained 22% and the second contained 30% of oxygen by weight. The ratio of weights of iron in the two oxides that combine with the same weight of oxygen, is [J&K CET]

(a) 3 : 2 (b) 2 : 1 (c) 1 : 2 (d) 1 : 1

6. The largest number of molecules is in [AMU]

(a) 34 g of OH2 (b) 28 g of 2CO (c) 46 g of OHCH3 (d) 54 g of 52ON

7. The equivalent weight of a metal is 9 and vapour density of its chloride is 59.25. The atomic weight of metal is [DIMET] (a) 23.9 (b) 27.3 (c) 36.3 (d) 23.6

8. 1.520 g of hydroxide of a metal on ignition gave 0.995 g of oxide. The equivalent weight of metal is [JCECE] (a) 1.52 (b) 0.995 (c) 190 (d) 9

9. The weight of one molecule of a compound 12260HC is [BHU]

(a) g103.1 20−× (b) g1001.5 21−

× (c) g1072.3 13−× (d) g104.1 21−

×

10. The crystalline salt OxH.SONa 242 on heating loses 55.9% of its weight. The formula of crystalline

salt is [Kerala CEE]

(a) OH5.SONa 242 (b) OH7.SONa 242 (c) OH2.SONa 242 (d) OH10.SONa 242

11. 25 g of 4MCl contains 0.5 mole chlorine then its molecular weight is [Punjab PMET]

(a) 100 g 1mol− (b) 200 g 1mol− (c) 150 g 1mol− (d) 400 g 1mol−

12. What is the percentage of cation in ammonium dichromate? [Kerala CEE]

(a) 14.29% (b) 80% (c) 50.05% (d) 20.52% (e) 25.62% 13. Which among the following is the heaviest? [Kerala CEE] (a) 1 mole of oxygen (b) 1 molecule of sulphur trioxide (c) 100 u of uranium (d) 44 g of carbon dioxide

14. A gas is found to have a formula x)CO( . If its vapour density is 70, the value of x is [AMU]

(a) 2.5 (b) 3.0 (c) 5.0 (d) 6.0

(23)

15. The ability of a given substance to assume two or more crystalline structure is called [AMU]

(a) amorphism (b) isomorphism (c) polymorphism (d) isomerism

16. In the equation, SNO2OH2HNO2SH 2232 ++→+ , the equivalent weight of hydrogen sulphide

is [BCECE]

(a) 18 (b) 68 (c) 34 (d) 17

17. The equivalent weight of phosphoric acid )POH( 43 in the reaction, [BHU]

OHPONaHPOHNaOH 24243 +→+ is

(a) 59 (b) 49 (c) 25 (d) 98

18. The standard adopted method for the determination of atomic weight of elements is based on

[JCECE]

(a) 1H (b) 12C (c) 16O (d) 32S

19. 1.0 g of magnesium is burnt with 0.56 g 2O in a closed vessel. Which reactant is left in excess and

how much? (Atomic weight, Mg = 24, O = 16) [CBSE AIPMT]

(a) Mg, 0.16 g (b) ,O2 0.16 g (c) Mg, 0.44 g (d) 2O , 0.28 g

20. When 22.4 L of )g(H2 is mixed with 11.2 L of )g(Cl2 , each at STP, the moles of HCl(g) formed is

equal to [CBSE AIPMT]

(a) 1 mole of HCl (g) (b) 2 moles of HCl (g) (c) 0.5 mole of HCl(g) (d) 1.5 mole of HCl(g)

21. 10 g of a mixture of BaO and CaO requires 100 3cm of 2.5 M HCl to react completely. The percentage of calcium oxide in the mixture is approximately [KCET]

(given, molar mass of BaO = 153)

(a) 52.6 (b) 55.1 (c) 44.9 (d) 47.4

22. In a closed vessel, 5 moles of )g(A2 and 7 moles of )g(B2 are reacted in the following manner,

)g(AB2)g(B3)g(A 322 →+

What is the total number of moles of gases present in the container at the end of the reaction?

[EAMCET]

(a) 22/3 (b) 7/3 (c) 14/3 (d) 8/3

23. Cyclohexanol is dehydrated to cyclohexane on heating with conc. 42SOH . If the yield of this

reaction is 75%, how much cyclohexene will be obtained from 100g of cyclohexanol? [WB JEE]

(a) 61.5 g (b) 75.0 g (c) 20.0 g (d) 41.0 g

24. In the synthesis of ammonia [KCET]

)g(NH2H3)g(N 322 +

If the quantity of 2N reacted is 700 mL, the quantity of 2H and 3NH would be

(a) 300 mL 2H and 200 mL 3NH (b) 300 mL 2H and 300 mL 3NH

(c) 300 mL 2H and 100 mL NH (d) 100 mL 2H and 200 mL 3NH

25. A metal oxide has the formula 32OA . It can be reduced by hydrogen to give free metal and water

.0.1596 g of this metal oxide requires 6 mg of hydrogen for complete reduction. What is the atomic weight of metal? [AIIMS]

(a) 52.3 (b) 57.3 (c) 55.8 (d) 59.3

(24)

26. 20.0 kg of )g(N2 and 3.0 kg of of )g(H2 are mixed to produce )g(NH3 . The amount of )g(NH3

formed is [Kerala CEE]

(a) 17 kg (b) 34 kg (c) 20 kg (d) 3 kg

27. Stoichiometric ratio of sodium dihydrogen orthophosphate and sodium hydrogen orthophosphate

required for synthesis of 1035 OPNa is [Guj CET]

(a) 1.5 : 3 (b) 3 : 1.5 (c) 1 : 1 (d) 2 : 3

28. If 1 mL of water contains 20 drops then number of molecules in one drop of water is [AFMC]

(a) 2310023.6 × molecules (b) 2610376.1 × molecules

(c) 1810344.1 × molecules (d) 2010346.4 × molecules

29. Volume of gas at NTP is 37 cm1012.1 −× . The number of molecules in it is [Manipal]

(a) 121001.3 × (b) 241001.3 × (c) 231001.3 × (d) 201001.3 ×

30. A mixture of 2CaCl and NaCl weighing 4.44 g is treated with sodium carbonate solution to

precipitate all the +2Ca ions as calcium carbonate. The calcium carbonate, so obtained is heated strongly to get 0.56 g of CaO. The percentage of NaCl in the mixture (atomic mass of Ca = 40) is [KCET]

(a) 75 (b) 30.6 (c) 25 (d) 69.4

31. 1 L oxygen gas at STP will weigh [JCECE]

(a) 1.43 g (b) 2.24 g (c) 11.2 g (d) 22.4 g

32. The number of moles of 2H in 0.224 L of hydrogen gas at STP (273 K, 1 atm) is [JCECE]

(a) 0.1 (b) 0.01 (c) 0.001 (d) 1

33. If the density of water is 1 g 3cm− then the volume occupied by one molecule of water is approximately [CMC Ludhiyana]

(a) 18 3cm (b) 22400 3cm (c) 323 cm1002.6 −× (d) 323 cm100.3 −

×

34. 10 g of hydrogen and 64 g of oxygen were filled in a steel vessel and exploded. Amount of water produced in this reaction will be [CBSE AIPMT]

(a) 3 mol (b) 4 mol (c) 1 mol (d) 2 mol

35. x moles of potassium dichromate oxidizes 1 mole of ferrous oxalate in acidic medium. Here x is

[AIIMS]

(a) 3 (b) 1.5 (c) 0.5 (d) 1.0

36. The equivalent weight of 4MnSO is half of its molecular weight when it is converted to [AFMC]

(a) 32OMn (b) 2MnO (c) −4MnO (d) −2

4MnO

37. What volume of 2CO will be liberated at NTP, if 12 g of carbon is burnt in excess of oxygen?

[AFMC]

(a) 11.2 L (b) 22.4 L (c) 2.24 L (d) 1.12 L

38. The number of electrons required to reduce 5105.4 −× g of Al is [MHT CET]

(a) 181003.1 × (b) 181001.3 × (c) 261095.4 × (d) 201031.7 ×

39. The mass of oxygen that would be required to produce enough CO which completely reduces 1.6

kg 32OFe (atomic mass of Fe = 56), is [Manipal]

(a) 240 g (b) 480 g (c) 720 g (d) 960 g

(25)

40. How much volume of oxygen at STP (in litres) is required to burn 4 g of methane gas completely?

[J&K CET]

(a) 11.2 (b) 5.6 (c) 2.8 (d) 82008

41. Excess of carbon dioxide is passed through 50 mL of 0.5 M calcium hydroxide solution. After the

completion of the reaction, the solution was evaporated to dryness. The solid calcium carbonate

was completely neutralized with 0.1 N hydrochloric acid. The volume of hydrochloric acid

required is (Atomic mass of calcium = 40) [KCET]

(a) 200 3cm (b) 500 3cm (c) 400 3cm (d) 3cm300

42. 100 mL of 3PH on heating forms P and 2H , the volume change in the reaction is [DUMET]

(a) an increase of 50 mL (b) an increase of 100 mL

(c) an increase of 150 mL (d) a decrease of 50 mL

43. Number of moles of −4MnO required to oxidize one mole of ferrous oxalate completely in acidic

medium will be [CBSE AIPMT]

(a) 0.6 mol (b) 0.4 mol (c) 7.5 mol (d) 0.2 mol

44. What volume of oxygen gas )O( 2 measured at C0o and 1 atm, is needed to burn completely 1 L

of propane gas )HC( 83 measured under the same conditions? [CBSE AIPMT]

(a) 7 L (b) 6 L (c) 5 L (d) 10 L

45. How many moles of lead (II) chloride will be formed from a reaction between 6.5 g of PbO and 3.2

g of HCl? [CBSE AIPMT]

(a) 0.044 (b) 0.333 (c) 0.011 (d) 0.029

46. In an oxidation-reduction reaction, −4MnO ion is converted to +2Mn .What is the number of

equivalents of 4KMnO (mol. wt. = 158) present in 250 mL of 0.04 M 4KMnO solution? [MP PMT]

(a) 0.02 (b) 0.05 (c) 0.04 (d) 0.07

47. The stoichiometry of the following reaction is )aq(I)aq(SOK2)aq(KI2)aq(OSK 242822 +→+

[J&K CET]

(a) 2 : 2 (b) 1 : 1 (c) 1 : 2 (d) 2 : 1

48. 40 g of a sample of carbon on combustion left 10% of it unreacted. The volume of oxygen required

at STP for this combustion reaction is [EAMCET]

(a) 22.4 L (b) 67.2 L (c) 11.2 L (d) 44.8 L

49. −+++→ eFeFe 32 ,

+−−→+

24 Mne5MnO

The ratio of stoichiometric coefficient of +2Fe and −4MnO is [DUMET]

(a) 1 : 5 (b) 5 : 1 (c) 2 : 3 (d) 6 : 1

50. For the reaction, 232 CO3Fe2CO3OFe +→+ , the volume of carbon monoxide reduce one mole

of ferric oxide is [KCET]

(a) 22.4 3dm (b) 44.8 3dm (c) 3dm2.67 (d) 11.2 3dm

51. What is the stoichiometric coefficient of Ca in the reaction? [UP CPMT]

AlCaAlCa 23+→+

++

(a) 2 (b) 1 (c) 3 (d) 4

(26)

52. 10 L of 2O gas is reacted with 30 L of CO gas at STP. The volumes of each gas present at the end of

the reaction are [Kerala CEE]

(a) CO = 10 L, 20CO2 = L (b) L30CO,L10O2 ==

(c) L20CO,L10O 22 == (d) L10CO,L10O2 ==

53. If equal volumes of 1 M 4KMnO and 1 M 722 OCrK solutions are allowed to oxidize Fe (II) to Fe

(III) in acidic medium then, Fe (II) oxidized will be [EAMCET]

(a) more by 4KMnO (b) more by 722 OCrK

(c) equal in both the cases (d) cannot be determined

54. Assertion (A) In the iodometric titration, starch is used as an indicator. [AIIMS]

Reason (R) Starch is a polysaccharide.





55. Assertion (A) 722 OCrK is used as a primary standard in volumetric analysis. [AIIMS]

Reason (R) It has a good solubility in water.





56. 2.76 g of silver carbonate on being strongly heated yield a residue weighing [BHU]

(a) 2.16 g (b) 2.48 g (c) 2.64 g (d) 2.32 g

57. How many grams of NaOH will be required to neutralize 12.2 g benzoic acid? [MP PMT]

(a) 12.2 g (b) 16 g (c) 40 g (d) 4 g

58. Sodium bicarbonate on heating decomposes to form sodium carbonate, 2CO and water. If 0.2

moles of sodium bicarbonate is completely decomposed, how may mole of sodium carbonate is

formed? [J&K CET]

(a) 0.1 (b) 0.2 (c) 0.05 (d) 0.025

59. The decomposition of a certain mass of 3CaCO gave 11.2 3dm of 2CO gas at STP. The mass of

KOH required to completely neutralize the gas is [KCET]

(a) 56 g (b) 28 g (c) 42 g (d) 20 g

60. What is the weight of oxygen that is required for the complete combustion of 2.8 kg of ethylene?

[BCECE]

(a) 9.6 kg (b) 96.0 kg (c) 6.4 kg (d) 2.8 kg

61. 2 g of 2O at C27o and 760 mm of Hg pressure has volume [BCECE]

(a) 1.4 L (b) 2.8 L (c) 11.2 L (d) 22.4 L

(27)

Level Level Level Level –––– III (JEEIII (JEEIII (JEEIII (JEE----Advance)Advance)Advance)Advance)

Multiple Choice Questions with One Correct Answer

1. The volume of water which must be added to 40 mL of a 0.25 N 42SOH solution in order to make

an exact decinormal solution is

(a) 60 mL (b) 20 mL (c) 50 mL (d) 25 mL

2. A solution contains ethanol and water. The mole fractions of ethanol and water in the solution are 1/5 and 4/5 respectively. The mole percentage of ethanol is

(a) 20% (b) 40% (c) 80% (d) 50%

3. Calculate the molality of a sulphuric acid solution containing 25 g of sulphuric acid in 200 g of water. The molar mass of sulphuric acid is 98.0.

(a) 2.18 (b) 1.28 (c) 1.08 (d) 0.128

4. The density of 2.45 M aqueous methanol )( 3OHCH is 0.976 g/mL. What is the molality of the

solution ?)32( 3 =OHCH

(a) 27.3 m (b) 0.273 m (c) 7.23 m (d) 2.73 m

5. The molality of a sulphuric acid solution is 0.2 mol/kg. Calculate the total weight of the solution.

(a) 1000 g (b) 1098.6 g (c) 980.4 g (d) 1019.6 g

6. Equal volume of 1.0 N HCl, 0.50 M KOH and 1.0 N KCl are mixed. The normality of the KCl in the mixture is

(a) 0.5 (b) 0.25 N (c) 0.75 N (d) 1.0 N

7. The amount of 4KMnO required to prepare 100 mL of a 0.1 N solution in a strongly alkaline

medium is

(a) 1.58 g (b) 3.16 g (c) 0.52 g (d) 0.31 g

8. The amount of 4KMnO required to prepare 100 mL of a 0.1 N solution in an acidic medium is

(a) 3.16 g (b) 1.58 g (c) 0.316 g (d) 31.6 g

9. The amount of 722 OCrK required to prepare 500 mL of a 0.1 N solution in an acidic medium is

(a) 4.90 g (b) 0.245 g (c) 2.45 g (d) 0.49 g

10. 500 mL of a glucose solution contains 221002.6 × molecules. The concentration of the solution is

(a) 0.1 M (b) 1.0 M (c) 0.2 M (d) 2.0 M

11. A tothpaste has 0.2g 1−L of fluoride. The concentration of the fluride in ppm will be

(a) 250 (b) 200 (c) 400 (d) 1000

12. 1.0 g of limestone was neutralized by 25 mL of a 1.0 N HCl solution. The percentage of pure

3CaCO in the limestone is

(a) 17% (b) 73% (c) 83% (d) 58%

13. 4 mL of concentrated 42SOH having a density of 1.8 g/ mL was diluted to one litre. 25.0 mL of this

dilute solution needed 35.0 mL of an N/10 32CONa solution for complete neutralization. The

percentage purity of 42SOH is

(a) 95.28% (b) 98.48% (c) 87.78% (d) 90.76% 14. 0.84 g of 3MCO was neutralized by 40 mL of an N/2 HCl solution. The equivalent weight of the

metal is (a) 21 (b) 24 (c) 42 (d) 12

15. 20.0 mL of an N/10 NaOH solution neutralizes 25.0 mL of a dibasic acid (6 g/L) . The molecular weight of the dibasic acid is (a) 75 (b) 225 (c) 150 (d) 300

(28)

16. 0.84 g of an acid (molecular weight = 225) is diluted to 100.0 mL. 25.0 mL of this solution neutralizes 28.0 mL of a 0.1 N NaOH solution. The basicity of the acid is

(a) 2 (b) 3 (c) 4 (d) 1

17. 1.578 g Ba OHxOH 22 .)( neutralizes 40 mL of an N/4 3HNO solution. The value of x is (Ba = 137.4)

(a) 10 (b) 6 (c) 8 (d) 4

18. A ’10-volume’ 22OH solution is equal to

(a) 22)/%(3 OHww (b) 30 g/L 22OH (c) 1.76 N (d) all of these

19. The number of moles of 4KMO that can be made to react with one mole of 42SOH in an acidic

medium is

(a) 2/5 (b) 3/5 (c) 4/5 (d) 1

20. What is the normality of a 0.1 722 OCrKM solution used as a precipitating agent for ?2+Pb

(a) 0.2 N (b) 0.4 N (c) 0.6 N (d) 0.1 N

21. 0.16 g of a dibasic acid required 25 mL of decinormal NaOH for complete neutralization. The molecular weight of the acid is

(a) 32 (b) 64 (c) 128 (d) 256

22. What volume of 1 M 42SOH is required to neutralize 10 mL of a 1 M NaOH solution?

(a) 25mL (b) 20 mL (c) 10 mL (d) 5 mL

23. An aqueous solution of 6.3 g of oxalic acid dihydrate is made up to 250 mL. The volume of 0.1 N NaOH requred to completely neutralize 10 mL of this solution is

(a) 40 mL (b) 20 mL (c) 10mL (d) 4 mL

24. 4KMnO reacts with oxalic acid according to the equation

OH8CO10Mn2H16OC5MnO2 2222

424 ++→++++−−

Here, 20 mL of 0.1 4KMNOM is equivalent to

(a) 20 mL of 0.5 M 422 OCH (b) 50 mL of 0.1 M 422 OCH

(c) 50 mL of 0.5 M 422 OCH (d) 20 mL of 0.1 M 422 OCH

25. A 10-volume sample of an 22OH solution is approximately equal to

(a) 3% (w/v) (b) 30% (w/v) (c) 10% (w/v) (d) 5% (w/v)

26. HCl solutions A and B have cencentrations 0.5 N and 0.1 N respectively. The volumes of solution A and solution B required to make 2 L of a 0.2 N HCl solution are

(a) 0.5 L of A and 1.5 L of B (b) 1.5 L of A and 0.5 L of B

(c) 1.0 L of A and 1.0 L of B (d) 0.75 L of A and 1.25 L of B

27. Under similar conditions of pressure and temperature, 40 mL of slighty moist HCl (g) is mixed with 20 mL of ammonia gas. The final volume of the gas mixture at the same temperature are pressure will be

(a) 100 mL (b) 20 mL (c) 40 mL (d) 60 mL

28. The volume strength of a 1.5 22OHN solution is

(a) 4.8 (b) 8.4 (c) 3.0 (d) 8.0

29. When 22.4 L of )g(H2 is mixed with 11.2 L of )g(Cl2 , each at STP, the moles of HCl(g) formed is

equal to

(a) 1 mole of HCl (g) (b) 2 moles of HCl (g) (c) 0.5 mole of HCl(g) (d) 1.5 mole of HCl(g)

(29)

30. 10 g of a mixture of BaO and CaO requires 100 3cm of 2.5 M HCl to react completely. The percentage of calcium oxide in the mixture is approximately (given, molar mass of BaO = 153) (a) 52.6 (b) 55.1 (c) 44.9 (d) 47.4

31. In a closed vessel, 5 moles of )g(A2 and 7 moles of )g(B2 are reacted in the following manner,

)g(AB2)g(B3)g(A 322 →+

What is the total number of moles of gases present in the container at the end of the reaction? (a) 22/3 (b) 7/3 (c) 14/3 (d) 8/3

32. In the synthesis of ammonia

)g(NH2H3)g(N 322 +

If the quantity of 2N reacted is 700 mL, the quantity of 2H and 3NH would be

(a) 300 mL 2H and 200 mL 3NH (b) 300 mL 2H and 300 mL 3NH

(c) 300 mL 2H and 100 mL 3NH (d) 100 mL 2H and 200 mL 3NH

33. A metal oxide has the formula 32OA . It can be reduced by hydrogen to give free metal and water

0.1596 g of this metal oxide requires 6 mg of hydrogen for complete reduction. What is the atomic weight of metal?

(a) 52.3 (b) 57.3 (c) 55.8 (d) 59.3

34. Volume of gas at NTP is 37 cm1012.1 −× . The number of molecules in it is

(a) 121001.3 × (b) 241001.3 × (c) 231001.3 × (d) 201001.3 ×

35. What volume of oxygen gas )O( 2 measured at C0o and 1 atm, is needed to burn completely 1 L of

propane gas )HC( 83 measured under the same conditions?

(a) 7 L (b) 6 L (c) 5 L (d) 10 L

36. In an oxidation-reduction reaction, −4MnO ion is converted to +2Mn .What is the number of

equivalents of 4KMnO (mol. wt. = 158) present in 250 mL of 0.04 M 4KMnO solution?

(a) 0.02 (b) 0.05 (c) 0.04 (d) 0.07

37. The stoichiometry of the following reaction is )aq(I)aq(SOK2)aq(KI2)aq(OSK 242822 +→+

(a) 2 : 2 (b) 1 : 1 (c) 1 : 2 (d) 2 : 1

38. −+++→ eFeFe 32 ,

+−−→+

24 Mne5MnO

The ratio of stoichiometric coefficient of +2Fe and −4MnO is

(a) 1 : 5 (b) 5 : 1 (c) 2 : 3 (d) 6 : 1

39. 2.76 g of silver carbonate on being strongly heated yield a residue weighing

(a) 2.16 g (b) 2.48 g (c) 2.64 g (d) 2.32 g

40. How many grams of NaOH will be required to neutralize 12.2 g benzoic acid?

(a) 12.2 g (b) 16 g (c) 40 g (d) 4 g

41. The decomposition of a certain mass of 3CaCO gave 11.2 3dm of 2CO gas at STP. The mass of

KOH required to completely neutralize the gas is

(a) 56 g (b) 28 g (c) 42 g (d) 20 g

42. 2 g of 2O at C27o and 760 mm of Hg pressure has volume

(a) 1.4 L (b) 2.8 L (c) 11.2 L (d) 22.4 L

(30)

43. The normality of 0.3 M phosphorous acid )POH( 33 is, - (1999- 2 Marks)

(a) 0.1 (b) 0.9 (c) 0.3 (d) 0.6

44. The reaction, )aq(Cl2)aq(ClO)aq(ClO3 3−−−

+→ , is an example of (2001 S)

(a) oxidation reaction (b) reduction reaction

(c) disproportionation reaction (d) decomposition reaction

45. An aqueous solution of 6.3 g oxalic acid dihydrate is made up to 250 ml. The volume of 0.1 N NaOH required to completely neutralize 10 ml of this solution is (2001 S)

(a) 40 ml (b) 20 ml (c) 10 ml (d) 4 ml

46. In the standardization of 322 OSNa using 722 OCrK by iodometry, the equivalent weight of

722 OCrK is (2001 S)

(a) (molecular weight)/2 (b) (molecular weight)/6

(c) (molecular weight)/3 (d) same as molecular weight

47. How many moles of electron weight one kilogram? (2002 S)

(a) 2310023.6 × (b) 3110108.9

1× (c) 5410

108.9

023.6× (d) 810

023.6108.9

1×

×

48. Which has maximum number of atoms? (2003 S)

(a) 24g of C(12) (b) 56g of Fe(56) (c) 27 g of Al(27) (d) 108g of Ag(108)

49. Mixture X = 0.02 mol of ]SO)NH(Co[ 453 Br and 0.02 mol of 453 SO]Br)NH(Co[ was prepared in 2

litre of solution. (2003 S)

1 litre of mixture X + excess YNOAg 3 → .

1 litre of mixture X + excess ZBaCl2 →

No. of moles of Y and Z are

(a) 0.01, 0.01 (b) 0.02, 0.01 (c) 0.01, 0.02 (d) 0.02, 0.02

50. The pair of the compounds in which both the metals are in the highest possible oxidation state is (2004 S)

(a) −− 36

36 ])CN(Co[,])CN(Fe[ (b) −

422 MnO,ClCrO

(c) 23 MnO,TiO (d) 33

6 MnO,])CN(Co[ −

51. Consider a titration of potassium dichromate solution with acidified Mohr’s salt solution using diphenylamine as indicator. The number of moles of Mohr’s salt required per mole of dichromate is (2007)

(a) 3 (b) 4 (c) 5 (d) 6

52. In a compound C, H and N atoms are present in 9 : 1 : 3.5 by weight. Molecular weight of compound is 108. Molecular formula of compound is [2002]

(a) 262 NHC (b) NHC 43 (c) 286 NHC (d) 3129 NHC

53. With increase of temperature, which of these changes? [2002]

(a) molality (b) weight fraction of solute

(c) molarity (d) mole fraction

54. Number of atoms in 558.5 gram Fe (at. wt. of Fe = 55.85 g 1mol− ) is [2002]

(a) twice that in 60 g carbon (b) 2210023.6 ×

(c) half that in 8 g He (d) 2310023.65.558 ××

(31)

55. What volume of hydrogen gas, at 273 K and 1 atm. pressure will be consumed in obtaining 21.6 g of elemental boron (atomic mass = 10.8) from the reduction of boron trichloride by hydrogen? [2003]

(a) 67.2 L (b) 44.8 L (c) 22.4 L (d) 89.6 L

56. 25 ml of a solution of barium hydroxide on titration with a 0.1 molar solution of hydrochloric acid gave a litre value of 35 ml .The molarity of barium hydroxide solution was [2003]

(a) 0.14 (b) 0.28 (c) 0.35 (d) 0.07

57. 201002.6 × molecules of urea are present in 100 ml of its solution. The concentration of urea solution is [2004]

(a) 0.02 M (b) 0.01 M (c) 0.001 M (d) 0.1 M

(Avogadro constant, 123A mol1002.6N −

×= )

58. To neutralize completely 20 mL of 0.1 M aqueous solution of phosphorous acid )POH( 33 , the

value of 0.1 M aqueous KOH solution required is [2004]

(a) 40 mL (b) 20 mL (c) 10 mL (d) 60 mL

59. The ammonia evolved from the treatment of 0.30 g of an organic compound for the estimation of nitrogen was passed m 100 mL of 0.1 M sulphuric acid. The excess of acid required 20 mL of 0.5 M sodium hydroxide solution for complete neutralization. The organic compound is [2004]

(a) urea (b) benzamide (c) acetamide (d) thiourea

60. Two solutions of a substance (non electrolyte) are mixed in the following manner. 480 ml of 1.5 M first solution +520 ml of 1.2 M second solution. What is the molarity of the final mixture? [2005]

(a) 2.70 M (b) 1.344 M (c) 1.50 M (d) 1.20 M

61. If we consider that 1/6, in place of 1/12, mass of carbon atom is taken to be the relative atomic mass unit, the mass of one mole of the substance will [2005]

(a) be a function of the molecular mass of the substance

(b) remain unchanged

(c) increase two fold

(d) decrease twice

62. How many moles of magnesium phosphate, 243 )PO(Mg will contain 0.25 mole of oxygen atoms?

[2006]

(a) 21025.1 −× (b) 2105.2 −

× (c) 0.02 (d) 210125.3 −×

63. Density of a 2.05 M solution of acetic acid in water is 1.02 g/mL. The molality of the solution is

[2006]

(a) 2.28 mol 1kg− (b) 0.44 mol 1kg− (c) 1.14 mol 1kg− (d) 3.28 mol 1kg−

64. The density (in g 1mL− ) of a 3.60 M sulphuric acid solution that is 29% 42SOH (molar mass = 98 g

1mol− ) by mass will be [2007]

(a) 1.45 (b) 1.64 (c) 1.88 (d) 1.22

65. In the reaction, [2007]

)g(H3)aq(Cl6)aq(Al2)aq(HCl6)s(Al2 23

++→+−+

(a) 11.2 L )g(H2 at STP is produced for every mole HCl (aq) consumed

(b) 6 L HCl aq is consumed for every 3 L )g(H2 produced

(c) 33.6 L )g(H2 is produced regardless of temperature and pressure for every mole Al that reacts

(d) 67.2 )g(H2 at STP is produced for every mole Al that reacts.

(32)

66. Consider the following reaction: [JEE M 2013]

OH2

zyCO2xMnzHOyCxMnO 22

22424 ++→++

++−−

The value’s of x, y and z in the reaction are, respectively: (a) 5, 2 and 16 (b) 2, 5 and 8 (c) 2, 5 and 16 (d) 5, 2 and 8

67. A gaseous hydrocarbon gives upon combustion 0.72 g of water and 3.08 g of 2CO . The empirical

formula of the hydrocarbon is: [JEE M 2013]

(a) 42HC (b) 43HC (c) 56HC (d) 87HC

68. Experimentally it was found that a metal oxide has formula OM 98.0 . Metal M, present as +2M and

+3M in its oxide. Fraction of the metal which exists as +3M would be: [JEE M 2013]

(a) 7.01% (b) 4.08% (c) 6.05% (d) 5.08%

More Than One Answer Correct Type Questions

69. Avogadro’s Number is the number of molecules present in:

(a) 22.4 litres of a gas at NTP (b) 1 g-molecule of a substance

(c) 32 g of oxygen (d) none of the above

70. Which of the following is correct?

(a) g-mole molar mass = molar mass in g = mass of 231002.6 × molecules

(b) Mole = N molecule = 231002.6 × molecules

(c) Mole = g-molecules

(d) None of the above

71. 8 g of 2O has the same number of molecules as:

(a) 7g of CO (b) 14 g of CO (c) 28 g of CO (d) 11 g of 2CO

72. The eq. mass of a substance is the mass which either combines or displaces:

(a) 8 part of O (b) 2 part of H (c) 35.5 part of Cl (d) none of these

73. Select the correct statements:

(a) The fraction of the total number of atoms found in the form of a particular isotope is called natural abundance of that isotope.

(b) Atomic mass unit is defined as th12

1 mass of a C12 atom.

(c) Compressibility of a substance is a measure of change in density for a given change in pressure. (d) The mass fraction of oxygen in air is 0.222.

74. 10 g of NaCl is dissolved in 250 g water. The correct way to express concentration of NaCl in solution are:

(a) mass fraction = 0.04 (b) mole fraction = 0.0122

(c) molality = 0.684 (d) molarity = 0.684

75. Mark the correct statements:

(a) In a chemical reaction, the electric charge of the ions taking part is conserved.

(b) The reactant which first disappear during a chemical change is called limiting reagent.

(c) A molecular compound may contain molecule or ions.

(d) The amount of atoms, ions or molecules in a sample is expressed in mole.

(33)

76. A tooth paste containing fluoride in form of sodium mono fluoroortho phosphate FPONa 43 has

0.754 mL solution. Which of the following are correct for the given observation?

(a) The number of fluorine atoms present in 100 mL = 211062.6 ×

(b) The mass of FPONa 43 100 mL = 2.0 g

(c) The concentration of 11.0FPONa 43 = M

(d) Mole of FPONa 43 = mole of F = mole of P

77. 35 drops of a liquid having density 1.2 g/mL, mass 2.4 g. Assuming molar mass of liquid 70, select the correct statements:

(a) Volume of one drop of liquid = 0.057 mL

(b) Mass of one drop of liquid = 0.068 g

(c) Number of molecules in one drop of liquid = 201085.5 ×

(d) Number of molecules in 35 drop of liquid = 221005.2 ×

78. 11.2 litre of a gas at STP weighs 14g. The gases could be:

(a) 22HC (b) 2N (c) CO (d) 42HC

79. Which of the following have same number of significant figures:

(a) 231002.6 +× (b) 311031.9 −

× (c) 241066.1 −× (d) 0.050

80. 2 litre of 0.1 M 42SOH is allowed to react with 2 litre of 0.1 M NaOH. Select the correct statements:

(a) Molarity of 42SONa formed is 0.1 M

(b) Molarity of 42SOH left is 0.1 M

(c) Mass of 42SONa formed is 7.1 g

(d) Strength of 42SONa solution formed is 3.55 g 1litre−

81. One mole of oxygen gas at STP is equal to:

(a) 2310022.6 × molecules of oxygen (b) 2310022.6 × atoms of oxygen

(c) 16 g oxygen (d) 32 g oxygen

82. Select the correct statements while evaluating the problem:

(a) In multiplication, exponents of like bases are added

(b) In division, exponents of like bases are substracted

(c) Units can also be expressed with exponents, both positive and negative

(d) 1 metric ton = 63 10kg10 = g

Integer Type Questions:-

83. A student performs a titration with different burettes and finds titre values of 25.2 mL, 25.25 mL, and 25.0 mL. the number of significant figures in the average titre value is (2010)

84. Silver (atomic weight = 108 g 1mol− ) has a density of 10.5 g 3cm− . The number of silver atoms on a

surface of area 1210− 2m can be expressed in scientific notation as x10y × . The value of x is: (2010)

85. The difference in the oxidation numbers of the two types of sulphur atoms in 642 OSNa is (2011)

86. If the value of Avogadro number is 2310023.6 × 1mol− and the value of Boltzmann constant is 123JK10380.1 −−

× , then the number of significant digits in the calculated value of the universal gas constant is (JEE Adv. 2014)

(34)

#ANSWER-KEY#

Exercise-1

1. yx 2 2. 2124 OHC 3. c 4. D 5. a

6. (a) 3 (b) 1 (c) 1 (d) 2 (e) 1 (f) 2 (g) 1 (h) 5 (i) 1 (j) 2 (k) 3 (l) 2 (m) 2 (n) 3 (o) 3 (p) 3 (q) 5 (r) 3 7. due to least count of scale

8. (a) L100.5 3× (b) g100.3 4

× (c) m100.1 5× 9. Theoretical

10. (a) 61010.5 × (b) 31060.2 × (c) 41000.4 × 11. (a) 35.8 m (b) 0.00263 L (c) 3830 g (d) 1.28 kg 12. (a) 21 (b) 6.4 (c) 5.00 (d) 32 13. (a) 0.4924 (b) 0.0080 (c) 2.0 14. (a) 28.0 (b) 151 (c) 138.43 (d) 94.90 (e) 0.5 15. To give result with precision. 16. (a) 1.85 (b) 184 (c) 0.005 (d) 8810 (e) 1.83

17. To give result with precision. 18. (a) 19. do 20. CO and 2CO

Exercise-2

1. AAA N20,N10,N2

2. AN

3. 15, 5, 20 4. 200 gm

5. 2 AN

6. 2010023.6 × 7. 5.6 litre

8. 31043.7 −×

9. (i) ,105.123

× (ii) 23100.3 ×

10. AN6

11. AN44

12. (a) AN24 (b) AN71.1

13. AN5

14. AAA N140,N40,N50

15. (i) 138.6 (ii) 350.0 (iii) 240.8

16. AN5.5

17. (a) A19 N108.0 −

× (b) A18 N1072.6 −

×

(c) A19 N108.4 −

× (d) A19 N106.9 −

×

18. 28 : 17 19. 0.8 mole 20. 44.64 mole 21. 20.8 22. 1 : 16 : 2 23. 18 ml

24. 2310316.5 −×− gm.

25. .gm1099.1 23−×

26. 200 ml

27. 61082451.1 × 28. 35.458 amu 29. (a) 48 gm (b) 72 gm

30. 232322 1010036.2,1005018.1,107503.1 ××× , 231005018.1 ×

31. 135.04 32. 8.5 gm

33. 10109099.1 × years. 34. 320 gm, 3.265 gm

35. 0.234 gm, 8.34 310−× mole

36. 3.01 2110×

37. 4CH

38. b 39. a 40. d 41. d 42. d 43. c 44. c 45. b 46. a

47. 191046.2 ×

48. 241061.3 × , 1.806 2410× 49. a

(35)

Exercise-3

1. 1.103

2. 2.44

3. 14.48

4. 22.39 L

5. 4 gm

6. 0.437 mole

7. 68.6 gm

8. 1.61 L

9. 33.48 mole

10. 125 mole

11. c

12. a

13. c

Exercise-4

1. (i) 0.64 gm (ii) 1.634 gm (iii) 0.9922 gm

2. 11.6 gm

3. 1000 mole, 28000 gm

4. 5600 litre, 3733.33 litre

5. 20 mole

6. 1420 gm

7. 11200 litre, 5600 litre

8. 8.33 mole

9. 1760 gm

10. 11200 litre

11. 33.23 kg

12. 128 kg

13. 40 ml

14. 41 litres.

15. 42HC

16. 2.24 litres

17. 42HC

18. mole percent of 2H us also 75%

19. 16 mL

20. 4 : 1

21. 120 mL

22. 500 mL

23. 8 litres

24. HCl = 22.4 litres , 2H = 0.8 litres.

25. 5.6 litres

26. 125HC

27. 2O = 44.0%, 2H = 56%

28. 62HC

29. mL6:HC 22 , CO : 14 mL

30. 2N : 60% ; NO = 40%

31. 10 mL, 4 mL

32. 10 mL

Exercise-5

1. d

2. a

3. b

4. a

5. a

6. b

7. c

8. c

9. c

10. c

11. d

12. a

Exercise-6

1. 4.66, 8.0, 49, 35.5, 63, 32.66, 41, 66, 40, 37, 26, 58.5, 71

2. (a) 31.6 (b) 158 (c) 52.66

3. molecular wt.

4. 106

5. molecular wt/3

6. 60

7. 63

8. 12

9. 11.2 litre, 5.6 litre, 3.73 litre.

10. 4

11. (i) 2.24 lt. (ii) 22.4 lt.

(iii) 11.2 lt. (d) 5.6 lt.

12. gm1065.2 23−× .

13. 100

14. 41.35

15. 118.8

16. 1000

17. 40 amu & 10 amu

18. 15 %

19. 31.8

20. 33.9

21. 107108w

w

1

−

×

22. 9.06

23. 22NC

24. 15.28

(36)

25. m = 1.942, M = 1.81054, N = 3.62108 26. 0.53 27. 0.4 28. 0.2 29. 2.27

30. 0.2 31. 11096.9 −× 32. 0.4 m. 33. 0.2 M

34. 0.4M 35. 0.332 36. 0.2m 37. 1.96 38. 20 39. 5.6 gm 40. 8 M 41. Solute = 4g, Solvent = 146 g 42. 2M 43. 1.06 g 44. 278.9 g 45. 2.8 L HCl solution is limiting reagent 46. 87 ml 47. (i) m = 2.17, (ii) 6.25 M (iii) .0376 (iv) .0826 (v) 8% (vi) 16.67% (vii) 25 (viii) 36.25% (ix) 72.5 (x) 9.0625 48.15 mL 49. 54% 50. 62HC 51. 2.54 gram 52. 11.5 53. 25

54. 1.445M 55. 1.13m, 1.088 M 56. 13.15 M 57. 16.67 % 58. 670 mL [Hint : First determine the molarity of 95% 42SOH and then dilute to get the desired

solution] 59. 1.288 g 1mL− 60. 55.56 M 61. 166.67 ml solution 62. 200 ppm 63. 40% 64. Water = 0.5022; ethanoic acid = 0.3013; ethanol =01965

65. 2/1V/V 21 = 66. (i) 2 :3 (ii) 7:6 67. 1.33 kg 68. 1.039 g/cc

69. 5106.5 × gm 70. 1.95 ppm 71. 80.40

Level – I (JEE-Main & NEET) 1. b 2. a 3. c 4. a 5. a

6. d 7. d 8. a 9. a 10. c

11. d 12. b 13. c 14. b 15. d

16. b 17. a 18. d 19. a 20. b

21. d 22. c 23. a 24. c 25. d

26. b 27. c 28. b 29. d 30. c

31. c 32. a 33. c 34. b 35. d

36. a 37. a 38. d 39. d 40. c

41. b 42. a 43. c 44. c 45. c

46. b 47. c 48. a 49. c 50. d

Level – II (Old Year JEE-Main & NEET) 1. c 2. b 3. a 4. a 5. a 6. a

7. a 8. d 9. d 10. d 11. b 12. a

13. d 14. c 15. c 16. d 17. d 18. b

19. a 20. a 21. a 22. a 23. a 24. a

25. c 26. a 27. a 28. c 29. a 30. a

31. a 32. b 33. d 34. b 35. c 36. b

37. b 38. b 39. b 40. a 41. b 42. a

43. a 44. c 45. a 46. b 47. c 48. b

49. b 50. c 51. c 52. a 53. b 54. b

55. c 56. a 57. d 58. a 59. b 60. a

61. a

Level – III (JEE-Advance)

1. a 2. a 3. b 4. d 5. d 6. a 7. a 8. c 9. c 10. c 11. b 12. c 13. a

14. d 15. c 16. b 17. c 18. d 19. a 20. c 21. c 22. d 23. a 24. b 25. a 26. a

27. b 28. b 29. a 30. a 31. a 32. a 33. c 34. a 35. c 36. b 37. c 38. b 39. a

40. d 41. b 42. a 43. d 44. c 45. a 46. b 47. d 48. a 49. a 50. b 51. d 52. c

53. c 54. a 55. a 56. d 57. b 58. a 59. a 60. b 61. d 62. d 63. a 64. d 65. a

66. c 67. d 68. b 69. a,b,c 70. a,b,c 71. a,d 72. a,c 73. a,b,c,d 74. b,c 75. a,b,d 76. a,b,c,d 77. a,b,c,d 78. b,c,d

79. a,b,c 80. b,c,d 81. a,d 82. a,b,c,d 83. 3 84. 7 85. 5 86. 4

ENABLE PROGRAMME

Documents

Transcript of ENABLE PROGRAMME