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Golongan III A dan IV A

Kelompok 5 :

1. Enthen Pradyka (4301411004)

2. Karima Helviana .S (4301411006)

3. Nova Safitri (4301411027)4. Anna Nashrullah (4301411031)

5. Dwi Norma Gupitasari (4301411042)

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Properties of The Elements

Group 3

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Group 3. B, Al, Ga, In, Tl.

In group 3 the electronegativity of the metals is getting a bithigher, and the heavier metals Ga, In, and Tl are actually post-transition elements (they are close to Au), so have muchhigher electronegativity and a very different chemistry from B

and Al. They form trivalent cations that form very strongcomplexes:

Metal ion: Al(III) Ga(III) In(III) Tl(III)ionic radius (): 0.58 0.62 0.80 0.89

log K1(OH)- 9.0 11.4 10.6 13.4log K1(EDTA): 16.4 20.4 25.0 35.3

increasing electronegativity

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Boron

Boron is very different in its chemistry from the other members

of the group. While they all have preferred coordinationnumbers of 6, with occasional higher coordination numbers of 7or 8, boron always has a coordination number of four or less.Thus, B(III) in aqueous solution exists as B(OH)3(aq) at lower pH,and is too acidic to ever be protonated to yield a B3+ (aq) ion. Athigher pH (9.1) a water coordinated to B(OH)3 (aq) ionizes toyield the borate anion:

B(OH)3.OH2(aq) = [B(OH)4]- (aq) + H+ (aq) pKa = 9.1

boric acidborate anion

This behavior is readily understood in terms of the small size(ionic radius = 0.11 ) and high charge on B(III).

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B(III) forms compounds of considerable covalency, withelectronegativity = 2.0, and forms a reasonably stable hydride,as in Li[BH

4

], lithium borohydride. Here we have a Td

[BH4

]-anion, which is used in organic chemistry as a mild reductant.The chemistry of the boranes, those compounds involvingboron and hydrogen, is enormous. The structure of [B2H6] is

shown below.

Figure 9. B2H6,

showing the

bridging H-atoms,which donate

electron density

to the adjacent

B atom.

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Alumunium

Aluminum name derived

from the word which refers

alum double salt compoundKAl(SO4)2.12H2O. This wordcomes from the Latin meaning

alumen bitter salt. By

Humphry Davy, metal doublesalt is proposed to be

aluminum.

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Corrosion Resistant AluminumMetal corrosion resistant aluminum air, because the

reaction between the aluminum metal with air

oxygen oxidation produces Al2O3. This oxide layer

formed nonpori the metal wrap.

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Applications Alumunium

water purification KAl(SO4)2.12H2O

color dyeing industry

. fire extinguishing agent Al2(SO4)3

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How to make Alumunium

Aluminum is derived minerals on a large scale as bauxite(Al2O3. 2H2O). Bauxite contains Fe2O3, SiO2, and other impurities.So to be able to separate the pure aluminum from itscompounds form, these impurities must be separated from thebauxite. This is done with the Bayer process. This includes the

addition of a solution of sodium hydroxide (NaOH) whichproduces a solution of sodium silicate and sodium alumina. Ironis a residual byproduct obtained in solid form. When CO2 flowedsteadily generating solution, sodium silicate solution while

staying in the aluminum precipitated as aluminum hydroxide.Hydroxide can be filtered, washed and heated to form purealumina, Al2O3.

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The Tl(III) ion is stabilized by complexation with ligands, and isan extremely powerful Lewis acid. Because of its high

electronegativity, Tl(III) is classified as soft in HSAB, asreflected by its log K1 values with halide ions:

Metal ion: Al3+ Ga3+ In3+ Tl3+

log K1 (F-): 6.42 4.47 3.74 2.6

log K1 (Cl-): -1.0 0.01 2.32 6.72

HARD SOFT

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Applications

The most economically important compound of boron is

sodium tetraborate decahydrate Na2B4O7 10H2O, or

borax, used for insulating fiberglass and sodium perborate

bleach. Boric acid is an important compound used in

textile products.

Compounds of boron are used in organic synthesis, in themanufacture of a perticular type of glasses, and as wood

preservatives. Boron filaments are used for advanced

aerospace structures, due to their high-strenght and light

weight.

An early use of borax was to make perborate, the

beaching agent once widely used in household

detergents. Boron compound also came into the average

home in the guise of food preservatives, expecialy for

margarine and fish.

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Aluminum is used excessively in the modernworld, and the uses of the metal are extremelydiverse due to its many unusual combinations

of properties. It can be used in so many waysacross such a variety of domains, like in thehome, in transport, on land, sea and in air, andin industry and commerce.

Cooking EquipmentAluminumConductors

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One of the most common end uses of aluminum is packaging,

including drinks cans, foil wrappings, bottle tops and foil containers.

Each of these relies on aluminum to provide a way of containing the

food cleanly, and to protect it from changes in the local environment

outside the packaging. Aluminum's natural resistance to corrosions

aids it in its role in packaging (and many other areas), as unlike in

iron, aluminum oxide forms a protective and not destructive layer.Aluminum is also completely impermeable, (even when rolled into

extremely thin foil), and also doesn't let the aroma or taste out of

food packaging, the metal is non-toxic and aromaless itself too,

making it perfect for packaging.

Packa

ging

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Less force is needed to move a lighter object to a certain

acceleration than is needed to get a heavier object to the same

acceleration. As aluminum is so lightweight this means that less energy

needs to be used to move a vehicle made with aluminum than one made

from a heavier metal, say steel. Although aluminum isn't the strongest of

metals its alloys use other elements to pin dislocations in its structure toincrease its strength. Its corrosion resistance is an advantage in

transport (as well as packaging) as it makes painting planes

unnecessary saving some hundreds of kilograms of further weight.

Used in Aeroplanes.

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Buildings made with aluminium are virtually maintenance freedue to the strength of aluminium's corrosion resistance. Due tothis and its light weight it is used in cladding, windows, skylights,gutters, door frames, and roofing. Insulated aluminium claddingis also very thermally efficient, keeping homes warm in winter,and cool in summer. One layer of insulated aluminium claddingis as effective as four inches of brick or ten of stone. Aluminiumcan also be painted and used with other material to achieve aparticular effect on the appearance of a building. The metal is

extremely versatile and it can be curved, tapered, welded,bonded and cut to any shape to be used for a certain job.

Ideal in

construction

Building

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Aluminum also has further and uses in products used more readilyaround the home. Like all the other uses they relate specifically backto the properties of the metal. The material is used to make

saucepans, kitchen utensils, golf clubs, tennis bats, indoor andoutdoor furniture, fridges, and toasters.

Summary: Aluminum has a huge number of uses. These range fromall sorts of packaging, through to aeroplanes, cars and traincarriages. Aluminum is also vital in the building and constructionindustry and commonplace household objects. The key featuresthat lend aluminium to these uses are corrosion resistance, low

density, ductility, electrical conductivity and strength in alloys.

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The inert pair effect in Thallium(I):

For the first time we have to

consider the inert pair effect.Thus,for Tl, the most stable oxidationstate is not Tl(III) but Tl(I). The Tl(I)ion has an ionic radius of 1.50 ,

and so resembles K+

and Rb+

tosome extent in its chemistry. It doeshave some tendency towardscovalence (it is soft), and so formsmany complexes where it is bound

to soft donors such as S. At right isseen the complex of Tl(I) with thesulfur-donor macrocycle 9-ane-S3.

position of

lone pair

Figure 8. Structure of the

Tl(I) complex with the

S-donor macrocycle

9-ane-S3.

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Group 4

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The inert pair effect in Pb(II) and Sn(II):

The high electronegativity of these elements leads to a

strong inert pair in Sn and Pb. For Sn both the Sn(IV)abd Sn(II) state are relatively stable. For Pb, the Pb(IV)state is of rather low stability. Important Pb(IV)compounds are PbO2, which is important in thelead/acid battery, and Pb(CH

2CH

3)4

(tetraethyl lead),which used to be added to gasoline to prevent knock(premature ignition on compression). The lead/acidbattery works on the cell:

PbO2(s) + 4 H+(aq) + Pb(s) =2 Pb2+(aq) + 2 H2O E

o = +1.2 V

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The Pb(II) and Sn(II) ions display a sterically active inert pair,which means that in structures of the complexes of these cations,there is usually a gap in the coordination geometry which isoccupied by the lone pair. This resembles the structure of NH3 aspredicted by VSEPR, where the structure is derived from atetrahedron, with one site occupied by the lone pair. This is seen

in the structures below of the [SnCl3]- and the [Pb(C6H5)3]

- anions:

[SnCl3]- [Pb(C6H5)3]-

lone pair

Cl

Cl

Cl

Sn

phenyl

group

Pb

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BISMUTH

Consumer is a mixture of a metal with a low

melting point to fuse and automatic sprinkling

system. In medicine, this element is used for the

treatment of X-rays, wound dressings and

treatment of syphilis. permanent magnet made of

MnBi and produced by the U.S. Naval Surface

Weapons Center.

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