Cambridge IGCSE Chemistry - 0620 - Supplement Paper 2 2014 Summer Zone 2

Two gas jars each contain a different gas. The gas jars are connected and the cover slips are removed.

The diagram shows what happens to the particles of the gases.


Which process has occurred?
A chemical reaction
B condensation
C diffusion
D evaporation

A liquid is heated until it boils.

Which result shows that the liquid in the test-tube is pure water?
A Condensation forms at the top of the test-tube.
B Steam is produced.
C The thermometer reads 100 °C.
D There is nothing left behind in the test-tube.

Which two methods can be used to separate a salt from its solution in water?
1 crystallisation
2 decanting
3 distillation
4 filtration
A 1 and 2
B 1 and 3
C 2 and 3
D 3 and 4

Which statements about a phosphorus atom, $^{31}_{15}\text{P}$, are correct?

1. The nucleon number is 16.
2. The number of outer electrons is 5.
3. The proton number is 15.

A 1, 2 and 3
B 1 and 2 only
C 1 and 3 only
D 2 and 3 only

The diagrams show four particles.



Which two diagrams show atoms that are isotopes of each other?
A 1 and 2
B 1 and 3
C 2 and 3
D 2 and 4

The 'lead' in a pencil is made of a mixture of graphite and clay.

When the percentage of graphite is increased, the pencil slides across the paper more easily.
Which statement explains this observation?
A Graphite has a high melting point.
B Graphite is a form of carbon.
C Graphite is a lubricant.
D Graphite is a non-metal.

The electronic structures of two atoms, X and Y, are shown.
X and Y combine together to form a compound.
What is the type of bonding in the compound and what is the formula of the compound?

[Table_1]
| type of bonding | formula |
|----------------|---------|
| A | covalent | $X_2Y$ |
| B | covalent | $XY_2$ |
| C | ionic | $XY_2$ |
| D | ionic | $X_2Y$ |

The structure of an organic compound, X, is shown.
What is the molecular formula of X?
A C6H9 B C6H12 C C7H12 D C7H14

What is the relative molecular mass, $M_r$, of nitrogen dioxide?
A 15
B 23
C 30
D 46

Electrical cables are made from either ......1......., because it is a very good conductor of electricity, or from......2......., because it has a low density. Overhead cables have a ......3...... core in order to give the cable strength.

Which words correctly complete gaps 1, 2 and 3?

[Table_1]

What will be produced at the anode and at the cathode, if molten potassium chloride is electrolysed?
[Table_1]

Table:

Solutions of two chemicals are mixed. A reaction occurs and the temperature change is measured. Which statement is correct?
A. If the reaction is endothermic, the temperature decreases and energy is taken in.
B. If the reaction is endothermic, the temperature increases and energy is given out.
C. If the reaction is exothermic, the temperature decreases and energy is given out.
D. If the reaction is exothermic, the temperature increases and energy is taken in.

Power stations produce electrical energy from different fuels.
Which fuel causes least pollution to the atmosphere?
A. coal
B. fuel oil
C. natural gas
D. radioactive isotopes

A student was investigating the reaction between marble chips and dilute hydrochloric acid.
Which changes would reduce the rate of reaction?

Which equation shows an oxidation reaction?
A. $C + O_2 \rightarrow CO_2$
B. $CaCO_3 \rightarrow CaO + CO_2$
C. $CaO + 2HCl \rightarrow CaCl_2 + H_2O$
D. $N_2O_4 \rightarrow 2NO_2$

In separate experiments, a catalyst is added to a reaction mixture and the temperature of the mixture is decreased.
What are the effects of these changes on the rate of the reaction?

[Table_1]
| catalyst added | temperature decreased | |----------------|------------------------| | A | faster | | B | faster | | C | slower | | D | slower |

Different plants grow best under different pH conditions.
Which plant grows best in alkaline soil?

[Table_1: plant and the pH values]

The equation shows a reaction that is reversed by changing the conditions.

forward reaction
CuSO$_4$.5H$_2$O $\rightarrow$ CuSO$_4$ + 5H$_2$O

How can the forward reaction be reversed?

Element X forms an oxide, XO, that neutralises sulfuric acid. Which row describes X and XO?

[Table_1]:
| | element X | nature of oxide, XO |
|---|-----------|--------------------|
| A | metal | acidic |
| B | metal | basic |
| C | non-metal | acidic |
| D | non-metal | basic |

Copper carbonate reacts with dilute sulfuric acid to make copper sulfate.
$$\text{CuCO}_3(s) + \text{H}_2\text{SO}_4(aq) \rightarrow \text{CuSO}_4(aq) + \text{CO}_2(g) + \text{H}_2\text{O}(l)$$
Which row gives the correct order of steps for making copper sulfate crystals?
[Table_1]

Element X is a non-metal.
In which position of the Periodic Table could element X be found?
A at the bottom of Group I
B at the top of Group 0
C at the top of Group I
D in the transition elements

Aqueous sodium hydroxide is added to solid X and the mixture is heated.
A green precipitate is formed and an alkaline gas is given off.
Which ions are present in X?
A. $\text{NH}_4^+$ and $\text{Fe}^{2+}$
B. $\text{NH}_4^+$ and $\text{Fe}^{3+}$
C. $\text{OH}^-$ and $\text{Fe}^{2+}$
D. $\text{OH}^-$ and $\text{Fe}^{3+}$

A student carried out an experiment to find the order of reactivity of five metals. They were tested with cold water, hot water and steam and the results recorded in a table.

[Table_1]

What is the order of reactivity of these metals?

[Table_2]

Why is argon gas used to fill electric lamps?
A. It conducts electricity.
B. It glows when heated.
C. It is less dense than air.
D. It is not reactive.

An element melts at 1455°C, has a density of 8.90 g/cm$^3$ and forms a green chloride.
Where in the Periodic Table is this element found?

The diagrams show two items that may be found in the home. Each item contains zinc.

In which is zinc used as an alloy?

[Table_1]

Which object is likely to be made from stainless steel? [Image_1: Includes images labeled A, B, C, and D showing a bicycle chain, car body, can of beans, and teaspoon, respectively.]

Four reactions that take place in the blast furnace to produce iron are shown.
Which reaction is used to keep the furnace hot?

A $\text{C + O}_2 \rightarrow \text{CO}_2$
B $\text{CO}_2 + \text{C} \rightarrow \text{2CO}$
C $\text{Fe}_2\text{O}_3 + 3\text{C} \rightarrow \text{2Fe} + 3\text{CO}$
D $\text{Fe}_2\text{O}_3 + 3\text{CO} \rightarrow \text{2Fe} + 3\text{CO}_2$

The diagram shows a blast furnace.

In which part is iron ore changed to iron?

The diagram shows some uses of water in the home.

For which uses is it important for the water to have been treated?
A 1 only
B 2 only
C 3 only
D 1, 2 and 3

A piece of uncoated iron and three pieces of iron with various coatings were left exposed to the air.

Which piece of iron would rust?

A the painted piece
B the tin-coated piece
C the uncoated piece
D the zinc-coated piece

Which compound would not be an effective fertiliser?
A. ammonium nitrate, $NH_4NO_3$
B. calcium oxide, $CaO$
C. calcium phosphate, $Ca_3(PO_4)_2$
D. potassium nitrate, $KNO_3$

Sulfur dioxide, $SO_2$, nitrogen dioxide, $NO_2$, and carbon monoxide, $CO$, are air pollutants.
Which row correctly shows their major source?

[Table_1]

Which process does not produce carbon dioxide?
A. combustion of methane
B. fermentation of sugar
C. polymerisation of ethene
D. respiration

Which pollutant gas is produced by the decomposition of vegetation?
A. carbon monoxide
B. methane
C. nitrogen oxide
D. sulfur dioxide

Which diagram shows the structure of pentanoic acid?

The table shows the composition of four different types of petroleum (crude oil).
[Table_1]
Which type of petroleum is best for the motor vehicle industry?
A. Arabian Heavy
B. Arabian Light
C. Iranian Heavy
D. North Sea

The diagram shows the cracking of substance X.
Which type of organic compound is found in Y, which is not present in X?
A acid
B alcohol
C alkane
D alkene

In which reaction could one of the products belong to the same homologous series as the organic reactant?
A addition of steam to ethene
B combustion of an alkane
C cracking of an alkane
D polymerisation of ethene

Ethanol is produced from either ethene or sugar. Which type of chemical reaction is used in each case?

[Table_1]
The table provides the options:
| ethene \rightarrow ethanol | sugar \rightarrow ethanol |
| --- | --- |
| A | addition | fermentation |
| B | addition | fractional distillation |
| C | distillation | fermentation |
| D | distillation | fractional distillation |