Cambridge IGCSE Chemistry - 0620 - Supplement Paper 2 2012 Winter Zone 2

What are the processes W, X, Y and Z in the following diagram?

$$\text{solid} \overset{W}{\underset{Y}{\rightleftharpoons}} \text{liquid} \overset{X}{\underset{Z}{\rightleftharpoons}} \text{gas}$$

Part of the instructions in an experiment reads as follows.

Quickly add 50 cm$^3$ of acid.

What is the best piece of apparatus to use?

A a burette
B a conical flask
C a measuring cylinder
D a pipette

A mixture of sulfur and iron filings needs to be separated. The solubilities of sulfur and iron filings in water and carbon disulfide are shown in the table below.

[Table_1]

What are possible methods of separating the sulfur and iron filings?

[Table_2]

Which row gives the number of electrons in the outer electron shell of fluorine and of neon?

[Table_1]

Which statements comparing the properties of electrons, neutrons and protons are correct?
[Table_1]

The table shows the electronic structures of four atoms.
[Table_1]
Which two atoms combine to form an ionic compound?
A W and X
B W and Y
C X and Y
D X and Z

In the molecules $\text{CH}_4$, $\text{HCl}$ and $\text{H}_2\text{O}$, which atoms use all of their outer shell electrons in bonding?
A. C and Cl
B. C and H
C. Cl and H
D. H and O

A compound has the formula CH3CO2H.
How should the relative molecular mass, $M_r$, of this compound be calculated?
A 12 + 1 + 16
B 3(12 + 1) + 2(12 + 16) + 1
C (4 \times 12) + (2 \times 1) + 16
D (2 \times 12) + (4 \times 1) + (2 \times 16)

The diagram shows an electrolysis experiment using metals X and Y as electrodes.



One of the metals becomes coated with copper. Which metal becomes coated and which aqueous solution is used?

[Table_1]

metal | aqueous solution
A. X | CrCl₃
B. X | CuCl₂
C. Y | CrCl₃
D. Y | CuCl₂

The diagram shows the electrolysis of concentrated aqueous sodium chloride.
What is produced at each of the electrodes?

The diagrams show the difference in energies of the reactants and products in two types of reaction.



Which diagram and which type of energy change apply to a fuel burning in air?

[Table_1]

Which change is an oxidation?
A) FeO to Fe_2O_3
B) Fe_2O_3 to FeO
C) H_2O_2 to H_2O
D) H_2O to H_2

The diagram shows a match.
By striking the match, a chemical reaction takes place.
Which statements about the chemical reaction are correct?
[Table_1]
type of reaction | reason
A endothermic | because energy is used to strike the match
B endothermic | because energy is given out as the match burns
C exothermic | because energy is used to strike the match
D exothermic | because energy is given out as the match burns

Separate samples of anhydrous and hydrated copper(II) sulfate are heated.

Which shows the correct colour changes?
[Table_1]:
\begin{array}{|c|c|c|} \hline & \text{anhydrous copper(II) sulfate} & \text{hydrated copper(II) sulfate} \\ \hline A & \text{blue to white} & \text{white to blue} \\ \hline B & \text{no change} & \text{blue to white} \\ \hline C & \text{white to blue} & \text{blue to white} \\ \hline D & \text{white to blue} & \text{no change} \\ \hline \end{array}

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

[Table_1]

Which change does not increase the speed of reaction between zinc and hydrochloric acid?
A adding a catalyst
B decreasing the particle size of the zinc
C decreasing the temperature
D using more concentrated acid

Barium hydroxide is an alkali. It reacts with hydrochloric acid.
How does the pH of the hydrochloric acid change as an excess of aqueous barium hydroxide is added?
A The pH decreases from 14 and becomes constant at 7.
B The pH decreases from 14 to about 1.
C The pH increases from 1 and becomes constant at 7.
D The pH increases from 1 to about 14.

Which of these pairs of aqueous ions both react with dilute sulfuric acid to give a visible result?
A $Ba^{2+}$ and $Cl^{-}$
B $Ba^{2+}$ and $CO_3^{2-}$
C $NH_4^{+}$ and $Cl^{-}$
D $NH_4^{+}$ and $CO_3^{2-}$

A compound is a salt if it
A can neutralise an acid.
B contains more than one element.
C dissolves in water.
D is formed when an acid reacts with a base.

The table gives information about four elements.
Which element is a transition metal?

[Table_1: ['colour of element', 'electrical conductivity of element', 'colour of oxide']
['A', 'black', 'high', 'colourless']
['B', 'colourless', 'low', 'white']
['C', 'grey', 'high', 'red']
['D', 'yellow', 'low', 'colourless']]

The diagram shows an outline of the Periodic Table.

Which of the elements U, V, W, X and Y would react together in the ratio of 1:1?
A U and X B U and Y C V and Y D W and X

The element rubidium, Rb, is immediately below potassium in the Periodic Table.
It reacts with bromine to form the compound rubidium bromide.
Which descriptions of this compound are correct?
[Table_1]

[Table_1]:
| type of bond | formula | colour |
|--------------|---------|--------|
| A | covalent | RbBr | brown |
| B | covalent | RbBr$_{2}$ | white |
| C | ionic | RbBr | white |
| D | ionic | RbBr$_{2}$ | brown |

Brass is used in electrical equipment.
It contains two ......1...... elements. Together they form ......2...... .
Which words correctly complete gaps 1 and 2?

Why are weather balloons filled with helium rather than hydrogen?
A. Helium is found in air.
B. Helium is less dense than hydrogen.
C. Helium is more dense than hydrogen.
D. Helium is unreactive.

Some properties of aluminium are listed.
1. It has mechanical strength.
2. It conducts heat.
3. It is resistant to corrosion.
4. It has a low density.
Which properties make aluminium useful for making the bodies of aircraft?
A. 1, 2 and 3
B. 1, 2 and 4
C. 1, 3 and 4
D. 2, 3 and 4

Pieces of copper, iron, magnesium and zinc are added to separate test-tubes containing dilute hydrochloric acid.
Which test-tube contains iron and dilute hydrochloric acid?

The Basic Oxygen Process converts iron into steel.
In step 1, oxygen is blown into impure molten iron.
In step 2, oxides are removed by reaction with calcium oxide.



Which chemical reaction takes place in step 1 and which type of oxides are removed in step 2?

[Table_1]

What is the correct order of abundance of the gases in the air?
A. nitrogen → oxygen → argon → carbon dioxide
B. nitrogen → oxygen → carbon dioxide → argon
C. oxygen → nitrogen → argon → carbon dioxide
D. oxygen → nitrogen → carbon dioxide → argon

Which processes are used in the treatment of water?
A. filtration and chlorination
B. filtration and reduction
C. neutralisation and chlorination
D. neutralisation and reduction

A factory burns coal with a high sulfur content.
Which pollutant is most likely to lead to the death of trees?
A. carbon dioxide
B. carbon monoxide
C. lead compounds
D. sulfur dioxide

The diagram shows an experiment to investigate how paint affects the rusting of iron.

What happens to the water level in tubes P and Q?

Carbon dioxide is produced when dilute hydrochloric acid reacts with
A calcium sulfate.
B carbon.
C copper(II) carbonate.
D limewater.

The diagram shows two substances, X and Y, being heated together.
The Universal Indicator paper turns blue during the experiment.
What are substances X and Y?
A ammonium nitrate and hydrochloric acid
B ammonium nitrate and sodium hydroxide
C sodium carbonate and hydrochloric acid
D sodium carbonate and sodium hydroxide

A student is asked to draw a diagram showing the uses of limestone.



Which numbered lines show a correct use of limestone?
A 1 and 2 only
B 1 and 3 only
C 2 and 3 only
D 1, 2 and 3

Which properties of the different compounds in petroleum enable its separation into fractions?
1 boiling point
2 chain length
3 chemical reactivity
4 solubility in water
A 1 and 2 B 1 and 3 C 2 and 4 D 3 and 4

Which structure is correctly named?

A. Ethanoic acid
B. Ethene
C. Ethanol
D. Propane

Alkenes have the general formula $C_nH_{2n}$.
Which of the following is an alkene?
A $CH_2$      B $CH_4$      C $C_3H_6$      D $C_6H_6$

A hydrocarbon X is cracked to make Y and hydrogen.
Compound Z is formed by the addition polymerisation of Y.
To which homologous series do X, Y and Z belong?
[Table_1]
| | alkane | alkene |
|------|----------|----------|
| A | X, Y and Z | - |
| B | X and Y | Z |
| C | X and Z | Y |
| D | Y and Z | X |

Bitumen is a substance obtained from the fractional distillation of petroleum. Which row describes its boiling point and the size of its molecules?
[Table_1]
|boiling point | size of molecules|
|--|--|
|A| high | large |
|B| high | small |
|C| low | large |
|D| low | small |

Which row is correct for ethanol?
[Table_1]