Igcse Chemistry Topic 10 Metals Ans

8/10/2019 Igcse Chemistry Topic 10 Metals Ans

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IGCSE Revision Exercise (03-09)Topic 10: Metals

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May/Jun 2009

B

B


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3/49

Oct/Nov 2008

May/Jun 2008

B

C

B


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4/49

Oct/Nov 2007

C

B


5/49


5/49

May/Jun 2007

C

C

A


6/49


6/49

Oct/Nov 2006

B

B

B


7/49


7/49

May/Jun 2006

B

D

B


8/49


8/49

Oct/Nov 2005

May/Jun 2005

D

D

D

B


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9/49

Oct/Nov 2004

A

A


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10/49

May/Jun 2003

D

A

B


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11/49

C

A


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12/49

B


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Paper 3

Oct/Nov 2008

NR NR NR

NRNR

R R

R

R

Sn + 2Ag+ 2Ag + Sn

2+

Zn + 2AgNO3 Zn(NO3)2+ 2Ag


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There is electron loss / oxidation no. increases

Aluminium oxide makes aluminium unreactive.

Potassium loses one electron / has one valency electron

Calcium loses 2 electrons/ has 2 valency electrons

No reaction

Calcium oxide + water

2KNO2 O2

2CaO 4NO2 O2

Sn2+

is the oxidizing agent.

There is electron gain / oxidation no. decreases


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15/49

May/Jun 2006

X

W

Z

Y

Z

Y


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16/49

Oct/Nov 2005

5

Give a pop sound with burning splint.

Test with pH paper/ universal indicatorturn blue

I

Electrolysis of molten state of ore of X

Zinc + waterhydrogen + zinc hydroxide

Heat, steam

Sn + 2H2O H2 + Sr(OH)2

Cold water


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17/49

May/Jun 2005

2

5

Oct/Nov 2004

Ca Ca2+ 2e-


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18/49

May/Jun 2003

5

Zn(OH)2 ZnO + H2O

It will melt but does not decompose / does not react

The solid changes from blue to black, and brown gas is evolved.

metal hydroxide / hydroxide ions + hydrogen


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Paper 6

Oct/Nov 2009

(gas) syringe

conical flask

glowing splint ; relights


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20/49

Oct/Nov 2007

0

18

30

33

42

45

46


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21/49

All points plotted (2)

Smooth line (1)

6 minutes

37 cm3


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22/49

Oct/Nov 2006

24 56

25 41

23 69

32

16

46

magnesium

Greatest temp.difference

Gas evolved rapidly

hydrogen


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23/49

May/Jun 2005

0

15

45

61

73

74

80

80


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25/49

Oct/Nov 2004

hydrochloric acid

zinc

measuring cylinder

flask


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26/49

Uses of Metals

Paper 1

Oct/Nov 2009

D

B

D


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27/49

May/Jun 2009

C

C

D

D


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29/49


29/49

A

B

D

D


30/49


30/49

May/Jun 2008

D

A

D


31/49


31/49

Oct/Nov 2007

A

C


32/49


32/49

May/Jun 2007

A

D

C

B


33/49


33/49

Oct/Nov 2006

Oct/Nov 2006

C

B

A


34/49


34/49

Oct/Nov 2005

A

D

A


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36/49


36/49

B

B

C

D


37/49


37/49

Oct/Nov 2004

C

C

A


38/49


38/49

May/Jun 2003

D

D

D

D


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Paper 3

Oct/Nov 2009

D


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40/49

Oct/Nov 2008

Water / moisture, oxygen /air

Cover with plastic / alloying / anodic protection / sacrificial

protection / galvanising

Carbon /hydrogen / carbon monoxide

2Fe2O3+ 3C3CO2+ 4Fe

2 x 56 + 3 x 16 + 2(2+16) = 196

112 / 196 x 100 % = 57.14%

Form carbon dioxide

Form silica /silicon(IV) oxide

CaO + SiO2 to form slag.


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May/Jun 2008

Oct/Nov 2007

good electrical conductor,

ductile or malleable

corrosion resistance / good heat conductor /

high m.p./ b.p. / non-toxic

alloy

boiling, condensation

To get maximum yield of zinc by removing carbon dioxide and in

turn shifting equilibrium to the right.

galvanizing / sacrificial protection

make brass / alloy / dry cell


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42/49

May/Jun 2007

5

It cannot lose electrons because it receives electrons from the battery.

Sacrificial protection needs a more reactive metal in contact with

iron/steel, this metal corrodes instead of steel.

Cathodic protection needs an inert electrode and electricity.


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alumina sodium aluminate

iron(III) oxidefiltration

carbon

cathode

aluminium

cryolite

900-1000oC

Al3+

+ 3e-Al

Oxygen formed at anode reacts with the carbon anode to

from carbon dioxide.

low density / light

Malleable / ductile / corrosion resistance

For greater strength


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44/49

Oct/Nov 2006

May/Jun 2006

1

zinc

limestone

slag

iron ore

To make carbon monoxide

To burn/ provide heat

Machinery / cars / fridges

Cutlery / chemical plants


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45/49

Oct/Nov 2005

5

May/Jun 2005

5

Heat zinc blende in air to form oxide,

then reduce oxide with carbon

To make brass (alloy) / sacrificial protection / galvanizing

battery roof


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46/49

May/Jun 2003

2Fe2O3 + 3C 4Fe + 3CO2

Or, Fe2O3 + 3C 2Fe + 3CO

(ii) (higher in furnace) no oxygen left, carbon dioxide reacts with carbon (to give

carbon monoxide)

Or, incomplete combustion of carbon

Or, CO2+ C2CO / 2C + O22CO

Or, carbon dioxide reacts with carbon


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Paper 6

Oct/Nov 2007

Brown / red-brown / orange

Take the place of oxygen

100% x (150-125) / 150 = 16.67%

No effect

slower formation of rust


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Oct/Nov 2006

Faster formation of rust / more rust / water further up the tube

Brown / red-brown / orange

Take the place of oxygen

100% x (150-125) / 150 = 16.62%

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Igcse Chemistry Topic 10 Metals Ans