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CHAPTER 9 Manufactured substances in industryANSWER

Activity No. Answer

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1

(a) Contact Process

2 (b) Sulphur dioxide

(c ) 2SO2 + O2 2SO3(d) Vanadium (V) oxide(e) 450 - 550 oC(f) 1 atm(g) SO3 , H2S2O7 ,(h) H2S2O7 , 2H2SO4

3 Fertilisers ,detergent ,pesticides, synthetic fibre

paint pigment, electrolyte in lead acid accumulator

4 Sulphur dioxideLung diseaseAcid rain

5a) (i) Sulphur dioxide from the factory

Toxic waste from the factory(ii) Sulphur dioxide combine with rain water to produce

acid rain.

Acid rain causes lakes and rivers to be acidic which causesfish and other aquatic organisms to die.(iii) toxic waste caused fishes and aquatic organisms died.

21 Nitrogen gas and hydrogen gas

2 (i) N2 + 3H2 2NH3

(ii) Iron powder450 550 oC,200-500 atm

1:3

3Fertilisers

2NH3 + H2SO4 (NH4)2SO4Nitric acid(c) coagulation

4 Colourless,solublepungent,alkaline

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Activity No. Answer

5 i) (a) (NH4)3PO4(b) NH4NO3(c ) (NH4)2SO4

(ii) (NH4)3PO43(14) / 3(14) + 12(1) + 31 + 4(16) x 100 = 28.19%

NH4NO32(14) / 14 + 4(1) + 14 + 3(16) x 100 = 35.00%

(NH4)2SO42(14) / 2(14) + 8(1) + 32 + 4(16) x 100 = 21.21%

ii) Ammonium nitratePercentage of nitrogen is the highest.

3 Haber Process

N2 + 3H2 2NH3Hidrogen, Nitrogen450 550 oC200 500 atmIron powder

PropertiesColourless

Pungent smellWeak alkaliVery soluble in water

UsesManufacture of fertilizersManufacture of nitric acids

TestTurn moist red litmus blue.Form white fumes with HCl gas.

ReactionReact with acid to produce ammonium saltReact with metal ions to produce metal hydroxide

41 mixture of a pure metal with other metals in fixed quantities.

2 Ductile , malleableThe layers of atom can slide over each other

3Disrupt the orderly,Sliding

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Activity No. Answer

4 5 hardness, strengthcorrosionappearance6 Steel, (ii) carbon

(iii) Pewter, (iv) tin(v) Copper (vi) Zinc

(vii) Magnesium, (viii) Aircraft body frame, racing car tyre rim.

5 1 Long chain molecule, monomer

2 Polymerisation

3Naturally Occurring polymersProteinCarbohydratesNatural rubberSynthetic PolimersPlasticFibresSynthetic rubbers

4 Polyethylene - ethenePolypropylene - propenePolyvinylchloride chloroethenePolystyrene phenylethenePerspex methymethacrylateTeflon tetraflouroethene

5 Polyethylene plastic bags, plastic toys, plastic containers.Polypropylene plastic bottles, ropes, plastic chairsPolyvinylchloride water pipes, shoes, artificial leathers.Polystyrene Packaging materials, heat insulators.Perspex safety glass, air plane windows.Teflon coating for non stick pan.

6 1 Silica

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Activity No. Answer

2(a) Fused glass(b) Soda lime glass(c) Borosilicate glass

(d) Lead crystal glass

3 Ceramic

4 Aluminosilicate

5 Kaolinite

6(i) Very hard and strong but brittle(ii) Inert towards chemicals(iii) Very high melting point

(iv) Good electrical and heat insulators(v) Resist compression

7 1 (a) Glass silica(b) Ceramic aluminosilicate and feldspar(c) Types of glass Fused glass

Soda limeBorosilicateLead crystal glass

(d) Improved glass photochromic glass

(e) Examples tilesCementPorcelainBricks

(f) Improved ceramics superconductors

(g) Common properties:Very hard and strong but brittleInert towards chemicalsVery high melting pointGood electrical and heat insulatorsResist compression

(h) Differences:Glass is transparent but ceramic is opaqueCeramic can withstand higher temperature than normal glass.

8 1 Combining two or more

2 Optical, photochromic glass,reinforced concrete, superconductors,plastics reinforced with glass.

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Activity No. Answer

3 To overcome the weakness of a material and to make materialsstronger, more long-lastings and light for specific purposes.

4 a) Silver chloride

b) It turns dark when exposed to the sunlight but turns back to itsoriginal colour when the surrounding is dark.

5 Composition

(i) Stone, sand and cement.

(iii) Alloy or ceramics of metaloxide

(v) Glass or plastic that are

surrounded by a glasscladding.

(vi) Plastic glass

(viii) Silver chloride in glasscrystal

Uses

(ii) Building, bridge

(iv) Bullet train, medical magneticimaging devices

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(vii) Water tank, small boat,helmets

(ix) Optical lenses, lens incamera, windows

9 1 a i) Stanum

ii)

Stanum atom which is bigger in size disrupt the orderly arrangement ofthe atoms in copper.This reduces the sliding of the layers of copper atoms.

iii)

Pure copper Bronze

b i) Vinylchloride

Ethene

ii) Water pipe/ electric cables/ mats/ cloth hanger

C i) Hard but brittle/

Chemically inert/Does not conduct electric/Heat insulator

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Activity No. Answer

ii) Borosilicate glass

2 a Contact Process

b Sulphur trioxide

c Dissolving sulphur trioxide directly into water produces a lot of heat/The process is very exothermic.

d H2S2O7 + H2O 2H2SO4

e Y : AmmoniaZ : Ammonium sulphate

f SO2 + H2O H2SO3

3 a

b

c

d

R= 2.33 mm ; S=3.17 mm

(i) R is stronger and harder than S(ii) S is pure metal while R is a mixture of 2 or more metals or a metal

and a non-metal(i) S(ii) R to make parts of heavy machinery- to make bridges

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