PROGRAM KECEMERLANGAN KIMIA SMKTTA TEKNIK MENJAWAB SOALAN KERTAS 2& 3 KIMIADisediakan Oleh: Rudi Bin ZainalCommon mistakes for paper 2 and 3The question normally starts with a command word. Students must know the meaning of the command word to make sure that the answer given is according to the question’s requirement.Match the command word to the mark allocated foreach question.

What is meant by..(Definition)- Give the exact meaning

1. Define the meaning of nucleon number?Wrong answer: sum of proton number and neutron numberCorrect answer:

2. Define the meaning of melting point?Wrong answer: Melting point is the point where solid starts changes to liquid.Correct answer:

3. Define the meaning of empirical formulaWrong answer: show the simplest ratioCorrect answer:

4. Define the meaning of molecular formulaWrong answer: real number/actual number of atomCorrect answer:

5. Define the meaning of hydrocarbon?Wrong answer: Compound that consist of carbon and hydrogenCorrect answer:

1

6. What is the meaning of number of proton and number of nucleon referring to atom sodium?[number of proton sodium = 11, Number of neutron sodium = 12]

7. Explain the meaning of isotope with example that suitable.

Wrong answer: same number of proton but different number of nucleonCorrect answer:

8. Define the meaning of acid?Wrong answer: Substances that containing of hydrogen ionCorrect answer:

9. Define alloy?Wrong answer: mix of 2 metalCorrect answer:

10. Define the meaning of rate of reaction?Wrong answer: changes of reactant or product with time.Correct answer:

Name/State the name-Give the name , not the formula.

11. State the name of catalyst used in contact process?Wrong answer: V2O5, vanadium oxideCorrect answer:

12. Name the main element added to copper to form bronze.Wrong answer : Sn.Correct answer :

Simple Experiment /Chemical test

2

Tips : All the experiment/ chemical test must have procedure and result.

13. How to verify a gas that released in electrolysis and it is a chorine gas?

Wrong answer: test using blue litmus paper and it will change to red colour.

Correct answer:

14. How to verify hydrogen gas?Wrong answer: test using burning wooden splinterCorrect answer:

15. How to verify oxygen gas?wrong answer: test using glowing wooden splinter

Correct answer:

16. How to verified presence of iron(III) ion in aqueous? Wrong answer: add sodium hdroxide ecessively, coclate colour percipitate formed Correct answer:

17. How to verified presence of nitrate ion in aqueous?Wrong answer: add sulphuric acid and iron II sulphate, shakewell then add slowly sulphuric acid.Correct answer:

Write what is observed physically .

18. State one observation when magnesium powder is added tohydrochloric

acid. Wrong answer : Hydrogen gas is released.Correct answer :

Indicate the change of colour , give the initial and final colour of the substance/chemical.

3

19. What is the colour change of copper(II) suphate solution.

Wrong answer: The solution becomes colourlessCorrect answer : The blue colour of the solution becomes colourless

Give the answer with reasons to explain certain statement / fact / observation/ principal.

20. Explain why bronze is harder than pure copper [4 marks]Wrong answer: forein atoms will prevebt pure atoms from slide to each otherCorrect answer :- Copper atoms in pure copper are all of the same size and ...........1- they are arranged in layers that can slide easily when force is applied .......... 1- The presence of tin atoms in bronze that are different in size disturb the orderly arrangementof atoms in bronze. ..........1-This reduces the layer of atoms from sliding.

State the method to conduct the test , observation and conclusion.

21. Describe how to identify the ion present in the solution . [ 3 marks]

Correct Answer: - Pour in 2 cm3 of the solution in a test tube. Add a few drops of sodium Hydroxide solution and the test tube is shake the test tube .........1- A reddish brown precipitate formed. .........1- Fe3+ ions present…….1

22. Describe how to identify acid and alkali using chemicaltest?(3 marks)

4

23. Describe how to differ butane and butene acid in chemically( 3 marks)

Another example common mistakes that candidate do.

24. Write the electron arrangement of Sodium?Wrong answer: 2:8:1Correct answer

25. Draw the diagrammatic diagram of magnesium atom?(Protonnumber: 12)

Wrong answer:

26. What is the function of salt bridge?

Wrong answer: to complete the circuitCorrect answer:

5

Salt bridge

27. Sketch graph of temperature against time for melting point of naphthalene. Why at the melting point a substance, temperature of substance did not increase although heating is continuously?

Wrong answer: because heat is absorbed is used to overcome attraction of particlesCorrect answer:

28. Give 1 special characteristic for transition element with example.

Wrong answer:1) as catalyst in chemical reaction 2) Can form color solutionCorrect answer:

29. State the one use of sulphuric acidWrong answer: as fertilizer As battery carCorrect answer:

30. Explain this ionic equation Cu→ Cu 2+ Wrong answer: copper releases 2 electrons to become copper ionCorrect answer:

CHEM-DRAW 31. Tick (√) or (x) in box that provided for the correct

diagram of stop cork.

6

7

Glass wool + C2H5OH

Burette

Basin that containing water

Chips of porcelain

What is the mistakes student have done?

PAPER 2 – STRUCTURE

1 In an experiment to determine the empirical formula of an oxide of copper, the combustion tube with the porcelain dish is weighed. Oxide of copper is added into the porcelain dish and the tube is weighed again. The oxide of copper is heated strongly. After the set of apparatus cools down to room temperature the combustion tube with its content is weighed again.

The following data is obtained.

Mass of combustion tube + porcelain dish= 19.60 g

Mass of combustion tube + porcelain dish + oxide of copper= 25.68 gMass of combustion tube +porcelain dish + copper

= 24.46 g

(a) What is meant by empirical formula?……………………………………………………………………………………………………………………………………………………………………………………………………………………………………[ 1 mark ]

(b) Draw a labelled diagram of the set up of the apparatus for the experiment.

8

[ 2marks ]

(c) Calculate the empirical formula of the oxide of copper.Given that the relative atomic mass of O=16 , Cu=64

3marks

(d) Write the chemical equation for the reaction in the experiment.

……………………………………………………………………[1 mark ]

(e) Before oxide of copper is heated, hydrogen gas is allowed to pass through the apparatus until all the air in the combustion tube is completely removed.Describe the steps that should be taken to ensure that all air in the combustion tube has been removed.

………………………………………………………………………………

9

……………………………………………………………………………………………………………………………………………………[3 marks]

(f) Can the empirical formula of aluminium oxide be determined using the same method as above? Explainyour answer.

……………………………………………………………………[2 marks]

2 The figure shows part of the Periodic Table of Elements.V,W,X,Yand Z do not represent the actual symbol of the elements.1 18

2 13 14 15 16 17V X Z

Y

W

(a) Write the electron arrangement of Y ion.

…………………………………………………………………….[1 mark]

b (i) Which of the element is not chemically reactive.

……………………………………………………………………….[1 mark] (ii) Explain your answer in (b) (i).

.................................................

............................................................

.............. [1 mark] (c) V and W are located in the same group in thePeriodic Table of Elements.

(i) Which of the element is more reactive?

10

..............................................................................................................…......... [1 mark] (ii) Explain your answer in (c)(i).

…………………………………………………………………….................................

………………………………………………………………………….........................

…………………………………………………………………………........ [3 marks]

(d) V reacts with Y to form a compound.State one physical property of the compound formed.

………………………………………………………………………………….....[1 mark] (e) X reacts with Y to form a compound.Draw the electron arrangement for the compound formed.

[2 marks]

SECTION C (ESSAY QUESTIONS)1. a) Compare the physical states that exist in matter in terms of particle arrangement, forces of attraction betweenthe particles and the kinetic energy content.

11

[9marks](ans) : Matter exists in 3 physical states ; i.e. Solid, liquid, gas

Solid : Particles are compact and ……………………….. arranged .The attractive force is ………………. and the particles can only …………and vibrate in ………………….position. The kinetic energy is ………………….

Liquid : Particles are less compact and are ……… arranged in orderly manner.The attractive force is ………………………., The particles form …………… that move freely. The kinetic energy is …………………………

Gas : Particles are not arranged at all and are …………………………………….. The attractive force is very …………………….………….. The kinetic energy is very ………………………….……….

b) A solid has a melting point of 75 0C. Describe an experiment conducted in a laboratory to determine the melting point of solid X. Your answer must show how the melting point of solid A can be obtained. [11marks] (Ans) ; Materials :Apparatus : boiling tube, thermometer ……………….. , beaker ……….cm3 retort stand + clamp, ……………………. , …………………………Procedure :

12

1. ………………………… of solid X is filled into a boiling tube.

2. The thermometer is put into the boiling tube and the water is ………….

3. The content of the boiling tube is .……………………. from timeto time.

4. When the temperature reaches ……….. 0C, the stop watch is…………..

5. The heating temperature is recorded at an interval of ……….. seconds

until ………………….. 0C.

Results :

Time / sTemperature/0C

The heating graph of solid X is plotted: Temperature/0C

__________________________ time/s

The melting point of solid X is read from the flat section of the graph;

i.e. …………………………………

2.The table shows the proton number of atoms P, Q and R.

Element Proton

13

numberPQR

81217

(a) Based on electron arrangement, explain the formation of chemical bond between

(i) element P and element P

[5 marks](ii) element Q and element R [7 marks ]

(b) Gas P reacts with element Q to produce a white solid.

(i) Write a chemical equation for the reactionbetween gas P and element Q. (ii) State three physical properties of the whitesolid.

[4 marks]

(c) What is the position of element Q in the Periodic Table of the elements? Explain how do you obtain your answer.

[4 marks]

GUIDELINE FOR ANSWERING PAPER 3Structure Question 1/2 Test The Mastery of 11 Scientific Skills1. Observing2. Classifying3. Inferring

14

4. Measuring (burette , stopwatch, thermometer, voltmeter)5. Predicting6. Communicating( e.g construct table and draw graph)7. Space-Time Relationship8. Interpreting Data9. Defining Operationally10. Controlling Variables11. Hypothesizing

Each answer is allocated mark as follows: 3 marks/2 marks/1 mark/0 Score : 11 X 3 = 33

Question 3 (essay) Test The Mastery of Planning Experiment .Planning should include the following aspects :1. Aim of the experiment/Statement of the problem2. All the variables3. Statement of the hypothesis4. List of substances/material and apparatus – should be separated5. Procedure of the experiment6. Tabulation of data Score : (5 X 3) + 2 = 17

• The question normally starts with certain situation related to daily life.• Problem statement/ aim of the experiment / hypothesis and variable can be concluded from the situation given.• State all the variables− Manipulated variable :− Responding variable :− Constant variable : list down all the fixed variables to ensure the outcome of the responding variableis related only to the manipulated variables.• Separate the substances and apparatus• Procedure :− All the steps taken in the procedure must include the apparatus used, quantity and type of substance ( powder, solution, lumps … etc).

15

PAPER 31. The diagram below shows the apparatus set-up for the experiment to determine the freezing point of substance X.

The diagram below shows the thermometer reading for the cooling of substance X at certain time intervals.

16

thermometer

Substance X

Volumetric flask

90

95

85

0 Minute 1st minute 2nd Minute

3rd minute

85

90

80

85

90

80

85

90

80

85

90

85

90

80

75

80

70

70

75

65

4th minute

5th minute

6th minute

7th Minute

(a) Record the thermometer readings shown in the diagram above by completing the table below. (3 marks)

(b) Draw the graph of temperature against time on the graph paper provided.

[3 marks](c) Based on the graph in (b),

(i) State the change in temperature of substance X for the whole experiment.

...........................................................................................................

................

...........................................................................................................

................

...........................................................................................................

................ [3 marks]

(ii) State the inference for your answer in (c) (i) .

...........................................................................................................

................

...........................................................................................................

................ [3 marks]

(d) What is the freezing point of substance X? Show and label it on the graph how you obtained the answer.

............. …………………… …………………………………………………………… [3 marks]

(e) Based on this experiment, what is meant by freezing point?

... …… …………………………………………………………………………………

... …… ………………………………………………………………………………… [3 marks]

(f) If substance X is heated from room temperature until 100oC, what is the temperature when substance X starts to melt? Explain your answer.

....................... …………………………………………………………………………………[3 marks]

3

time/minute 0 1 2 3 4 5 6 7

Temperature/ oC

17

Elements in Group 1 of the Periodic Table of Elements can bearranged based on the reactivity of the elements with water.

An experiment is carried out to investigate the statement above.The table below shows the apparatus setup and the observations for the experiment to determinethe reactivity of the Group 1 elements based on their reactions with water.

Apparatus set-up Observation towards the metal

Lithium moves slowly on the surface of thewater with a hiss sound.“ ”

Potassium moves vigorously and randomly on the surface of the water with a hiss “ ”sound.

Sodium moves quickly and randomly on thesurface of the water with a hiss sound.“ ”

(a) State the variables that are involved in the experiment.

Name of variables Action to be taken(i) Manipulated variable:

……………………………………..

……………………………………..

(i) The way to manipulate variable:

………………………………………..

………………………………………...

(ii) Responding variable:

……………………………………

……………………………………

(ii) What to observe in the responding variable:………………………………………..

………………………………………..………

(iii) Controlled variable:

……………………………………..

(iii) The way to maintain the controlled variable:

………………………………………

18

water

water

))

sodium

)) )

)))

Potassium)) ) )

water

Lithium

……………………………………..………………………………………

[6 marks]

(b) State one hypothesis for the experiment.

……………………………………………………………………………………………………………………………………………………………………………… [3 marks]

(c) Based on the observations in the figure above, arrange lithium, potassium and sodium in the descending order of reactivity of metals towards water.

Descending order of reactivity of metals towards water. [3 markah]

(d) Solution X was produced from the reaction of sodium with water. Classify the ions that exist in solution X into positive ions and negative ions.

Positive Ions Negative Ions

[3 marks]

( Paper 3 )1

Covalent compounds are non-conductors of electricity in any state. Ionic compounds can conduct electricitywhen dissolved in water.

Referring to the above statement, design a laboratory experiment related to the electrical conductivity of ethanol and aqueous sodium nitrate solution.In designing your experiment, the following aspects must be included : a) Problem statementb) Hypothesis

19

c) List of substances and apparatusd) Experimental procedurese) Results

[Ans] :

a) Problem statement :

b) Hypothesis : …………………………. does not conduct electricity

whereas ………………………………………………………….

conducts electricity.

c) Substances :

Apparatus : beaker ……………….. cm3 , measuring cylinder ………...

cm3 , …………………………. , ………………………………….

light bulbs, switch, connecting wires with clips,

d) Experimental procedure :

1. ………………………. of ethanol is measured by a measuring

cylinder and is poured into a beaker.

2. Two ……………………………… rods are immersed in ethanol and

20

the circuit is completed by connecting to batteries, a switch and

a light bulb.

3. The switch is turned on and the bulb is checked if it is ………………

……………………………

4. The experiment is repeated by using ……………………………………e) Results

Chemical compound

Observation

Ethanol

Aqueous sodium Nitrate solution

21

“When lithium metal is put in water, it moves very slowly on the surface of the water. When sodium metal is put in water, it moves quite fast and produces “hiss” sound. When potassium metal is put in water, it moves very fast and produces small explosions”. Metal

2

Plan an experiment in the laboratory to investigate the reactivity of lithium, sodiumand potassium with water and describe the effect of the solution produced towards a red litmus paper. The planning of your experiment must consist of the following:

(a) Aim of experiment (b) Statement of the hypothesis (c) All the variables

(d) List of substances and apparatus(e) Procedure of the experiment(f) Tabulation of data

[17 marks]

QUESTIONS END

22

Water