Cambridge IGCSE Chemistry - 0620 - Supplement Paper 2 2009 Summer Zone 2

The diagram shows how the molecules in the exhaust gases diffuse into the air.
Which statement describes what happens to these molecules next?
A. The molecules fall to the ground because they are heavier than air molecules.
B. The molecules go back together as they cool.
C. The molecules spread further into the air.
D. The molecules stay where they are.

The diagram shows the paper chromatograms of four substances, W, X, Y and Z.
Which two substances are pure?
A. W and X
B. W and Y
C. X and Y
D. X and Z

A student takes 2 g samples of calcium carbonate and adds them to 20 cm³ samples of dilute hydrochloric acid at different temperatures. She measures how long it takes for the effervescence to stop.
Which apparatus does she use?

The diagrams show the structures of two forms, P and Q, of a solid element.

What are suitable uses of P and Q, based on their structures?
[Table_1]

An element S has the proton number 18. The next element in the Periodic Table is an element T.

Which statement is correct?

A. Element T has one more electron in its outer shell than element S.
B. Element T has one more electron shell than element S.
C. Element T is in the same group of the Periodic Table as element S.
D. Element T is in the same period of the Periodic Table as element S.

Element V forms an acidic, covalent oxide.
Which row in the table shows how many electrons there could be in the outer shell of an atom of V?
[Table_1]

Which numbers are added together to give the nucleon number of an ion?
A number of electrons + number of neutrons
B number of electrons + number of protons
C number of electrons + number of protons + number of neutrons
D number of protons + number of neutrons

When sodium chloride is formed from its elements, each chlorine atom ......1...... one ......2.......
Which words correctly complete gaps 1 and 2?
[Table_1]

The electronic configuration of an ion is 2.8.8.
What could this ion be?
[Table_1]

Nitrogen and hydrogen react together to form ammonia.
$$N_2 + 3H_2 \rightarrow 2NH_3$$
When completely converted, 7 tonnes of nitrogen gives 8.5 tonnes of ammonia.
How much nitrogen will be needed to produce 34 tonnes of ammonia?
A 7 tonnes B 8.5 tonnes C 28 tonnes D 34 tonnes

Which relative molecular mass, $M_r$, is not correct for the molecule given?
[Table_1]

Which of these elements could be formed at the anode when a molten salt is electrolysed?
A copper
B iodine
C lithium
D strontium

Aluminium is extracted from its oxide by electrolysis.
The oxide is dissolved in ......1...... cryolite and aluminium is deposited at the ......2......
Which words correctly complete gaps 1 and 2?

[Table_1]

Molten lead(II) bromide is electrolysed as shown. [Image_1: Diagram of an electrolytic cell with molten lead(II) bromide]
Which ions are discharged at each electrode?
[Table_1: Table showing ions at positive and negative electrodes]
A. Positive electrode: $\text{Pb}^{+}$, Negative electrode: $\text{Br}^{2-}$
B. Positive electrode: $\text{Pb}^{2+}$, Negative electrode: $\text{Br}^{-}$
C. Positive electrode: $\text{Br}^{2-}$, Negative electrode: $\text{Pb}^{+}$
D. Positive electrode: $\text{Br}^{-}$, Negative electrode: $\text{Pb}^{2+}$

Which diagram shows a process in which an endothermic change is taking place?

The diagram shows some properties that substances may have. To which labelled part of the diagram does $^{235}U$ belong?
[Image_1: Venn diagram with labels 'compound', 'used as an energy source', 'radioactive', and regions A, B, C, D]

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

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

How can the forward reaction be reversed?

[Table_1]

| | by adding water | by heating |
|---|----------------|------------|
| A | ✓ | ✓ |
| B | ✓ | ✗ |
| C | ✗ | ✓ |
| D | ✗ | ✗ |

Which does not increase the speed of a reaction?
A. adding a catalyst
B. increasing the concentration of one of the reactants
C. increasing the particle size of one of the reactants
D. increasing the temperature

The reactions shown may occur in the air during a thunder storm.

$$N_2 + O_2 \rightarrow 2NO$$
$$2NO + O_2 \rightarrow 2NO_2$$
$$NO + O_3 \rightarrow NO_2 + O_2$$

Which line shows what happens to the reactant molecules in each of these reactions?

[Table_1]

$$\begin{array}{|c|c|c|c|} \hline & N_2 & NO & O_3 \\ \hline A & \text{oxidised} & \text{oxidised} & \text{oxidised} \\ \hline B & \text{oxidised} & \text{oxidised} & \text{reduced} \\ \hline C & \text{reduced} & \text{reduced} & \text{oxidised} \\ \hline D & \text{reduced} & \text{reduced} & \text{reduced} \\ \hline \end{array}$$

Some reactions of a substance, R, are shown in the diagram.

What type of substance is R?
A an acid
B a base
C an element
D a salt

An element E is burned in air. A white solid oxide is formed. The oxide is tested with damp red litmus paper. The paper turns blue. What is element E?
A. calcium
B. carbon
C. iodine
D. sulfur

The graph shows how the pH of soil in a field changed over time.
At which point was the soil neutral?
[Graph displaying pH changes over time with points A, B, C, D]

Aqueous sodium hydroxide is added to a solution of a salt. A blue precipitate is formed which does not dissolve in excess.
Aluminium foil is added to the mixture and the mixture is warmed. A gas is produced that turns damp red litmus paper blue.
What is the name of the salt?
A. ammonium nitrate
B. ammonium sulfate
C. copper(II) nitrate
D. copper(II) sulfate

Which statement describes the trends going down group VII of the Periodic Table?
A The boiling point and melting point both decrease.
B The boiling point and melting point both increase.
C The boiling point decreases but the melting point increases.
D The boiling point increases but the melting point decreases.

The sulfate of element F is green.
Which other properties is element F likely to have?

[Table_1]

Which diagram represents the structure of an alloy?
[Image of diagrams A, B, C, D]

An inert atmosphere is needed in a lamp to lengthen the useful life of the metal filament.
Why is argon, rather than helium, used for this purpose?

In a blast furnace, iron(III) oxide is converted to iron and carbon monoxide is converted to carbon dioxide.
$$\text{Fe}_2\text{O}_3 + 3\text{CO} \rightarrow 2\text{Fe} + 3\text{CO}_2$$
What happens to each of these reactants?
A Both iron(III) oxide and carbon monoxide are oxidised.
B Both iron(III) oxide and carbon monoxide are reduced.
C Iron(III) oxide is oxidised and carbon monoxide is reduced.
D Iron(III) oxide is reduced and carbon monoxide is oxidised.

Which property do all metals have?
A) They are hard.
B) They conduct electricity.
C) They form acidic oxides.
D) They react with water.

Stainless steel is an alloy of iron and other metals. It is strong and does not rust but it costs much more than normal steel.
What is not made from stainless steel?
A cutlery
B pipes in a chemical factory
C railway lines
D saucepans

The table gives information about three different metals G, H and J.

[Table_1]

metal | does it react with
| water | steam |
G | ✗ | ✗ |
H | ✓ | ✓ |
J | ✗ | ✓ |

key
✓ = does react
✗ = does not react

What is the order of reactivity of these metals?

[Table_2]

most reactive -> least reactive
A. G, H, J
B. H, G, J
C. H, J, G
D. J, H, G

The diagram shows stages in the purification of water.
Which stage uses chlorine?

Which statements are correct?
1. Carbon monoxide is responsible for the production of 'acid rain'.
2. Oxides of nitrogen are present in car exhausts.
3. Sulfur dioxide can be produced by the combustion of fossil fuels.
A. 1 and 2 only
B. 1 and 3 only
C. 2 and 3 only
D. 1, 2 and 3

Substance K reacts with sodium carbonate to form a gas.
The gas turns limewater cloudy.
What is substance K and which process takes place in the reaction?
[Table_1]

An iron nail is placed in a closed test-tube, containing gas L. The nail rusts.

What is gas L?
A carbon dioxide
B hydrogen
C nitrogen
D oxygen

A compound has the formula CH₃CH₂CH=CH₂.
Which row in the table shows the type of compound and the colour change when aqueous bromine is added?

[Table_1]

Which element is not added to a fertiliser?
A aluminium
B nitrogen
C phosphorus
D potassium

The structures of three compounds are shown.

Why do these substances all belong to the same homologous series?
A They all contain an even number of carbon atoms.
B They all contain the same functional group.
C They are all hydrocarbons.
D They are all saturated.

Which bond is not in a molecule of ethanoic acid?
A. C–O
B. C=O
C. C=C
D. O–H

The diagram shows an industrial process. Substance M is one of the substances produced by this process and is used as aircraft fuel.
What is this process and what is substance M?
[Table_1:
| Process | Substance M |
|:---------------------:|:-----------:|
| A) Fractional distillation | Paraffin |
| B) Fractional distillation | Petrol |
| C) Thermal decomposition | Paraffin |
| D) Thermal decomposition | Petrol | ]