Cambridge IGCSE Chemistry - 0620 - Supplement Paper 2 2015 Summer Zone 1

The changes that occur when a substance changes state are shown below.



Which process, W, X, Y or Z, is occurring in the following four situations?

1. Butter melts on a warm day.
2. Water condenses on a cold surface.
3. The volume of liquid ethanol in an open beaker reduces.
4. Ice forms inside a freezer.

[Table_1]

A student uses the apparatus shown in the diagram below to measure the volume of carbon dioxide gas made when different masses of marble chips are added to 25 cm³ of dilute hydrochloric acid.
Which other items of apparatus are needed?
A funnel and balance
B funnel and stopwatch
C measuring cylinder and balance
D measuring cylinder and stopwatch

Atoms contain electrons, neutrons and protons. What is the definition of nucleon number?
A the number of neutrons in the nucleus of an atom
B the number of protons in the nucleus of an atom
C the total number of neutrons and protons in the nucleus of an atom
D the total number of particles in an atom

The diagram shows the atomic structure of an element X.
What is X?
A. aluminium
B. beryllium
C. boron
D. fluorine

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

[Table_1]

Table:
| | neutrons and protons are both heavier than electrons | only electrons and neutrons are charged |
|---|---------------------------------------------------|--------------------------------------|
| A | ✓ | ✓ |
| B | ✓ | ✗ |
| C | ✗ | ✓ |
| D | ✗ | ✗ |

Rescuers are drilling through fallen rock in order to rescue some men trapped in a cave. The drill needs lubricating from time to time.

The following statements were made about the materials used for the drill tip and the lubricant and the reasons for their use.

1 Diamond was used for the drill tip as it does not conduct electricity.
2 Diamond was used for the drill tip as it is very hard.
3 Graphite was used as the lubricant as it conducts electricity.
4 Graphite was used as the lubricant as it is soft and flaky.

Which statements are correct?
A 1 and 3 B 1 and 4 C 2 and 3 D 2 and 4

In which compounds are pairs of electrons shared between atoms?
1. methane
2. lead bromide
3. sodium chloride
A. 1 only
B. 2 only
C. 1 and 3
D. 1, 2 and 3

What is the relative formula mass, $M_r$, of $CaCO_3$?
A. 50
B. 68
C. 100
D. 204

Copper and hydrogen can each be formed by electrolysis. At which electrodes are these elements formed?
[Table_1]

The diagram shows a failed attempt to copper-plate a pan.

Which action will plate the pan with copper?
A. cooling the copper sulfate solution in an ice bath
B. heating the copper sulfate solution to boiling point
C. increasing the voltage from 3 V to 6 V
D. making the pan the cathode and the copper the anode

The diagrams show four chemical reactions. Which reaction is endothermic?

Powdered marble reacts with hydrochloric acid using the apparatus shown. The gas syringe fills in 36 seconds. The experiment is repeated using marble chips in place of powdered marble. How long does it take to fill the gas syringe in this experiment?
A. 9 seconds
B. 18 seconds
C. 36 seconds
D. 72 seconds

When pink crystals of cobalt(II) chloride are heated, steam is given off and the colour of the solid changes to blue.
$$\text{CoCl}_2 . 6\text{H}_2\text{O} \rightleftharpoons \text{CoCl}_2 + 6\text{H}_2\text{O}$$
What happens when water is added to the blue solid?

[Table_1]
| colour | temperature |
|---------------- |--------------|
| A | changes to pink | decreases |
| B | changes to pink | increases |
| C | remains blue | decreases |
| D | remains blue | increases |

In which change is chromium(II) oxide, CrO, reduced?
[Image_1: A diagram showing various pathways involving Cr, CrO, CrO_2, Cr_2O_3, CrO_3 with arrows labeled A, B, C, D]
Pathways:
A: Cr to CrO
B: CrO to CrO_3
C: CrO to CrO_2
D: CrO to Cr_2O_3

The table shows the pH of four aqueous solutions, W, X, Y and Z.
[Table_1]
Universal Indicator is added to each solution.
Which row shows the colour of each solution after the indicator is added?
[Table_2]

Hydrochloric acid is used to clean metals.
The acid reacts with the oxide layer on the surface of the metal, forming a salt and water.
Which word describes the metal oxide?
A alloy
B base
C element
D indicator

Four steps to prepare a salt from an excess of a solid base and an acid are listed.
1 crystallisation
2 evaporation
3 filtration
4 neutralisation
In which order are the steps carried out?
A 2 → 3 → 4 → 1
B 3 → 1 → 2 → 4
C 4 → 2 → 1 → 3
D 4 → 3 → 2 → 1

Which two compounds give a white precipitate when their aqueous solutions are mixed?
A. Silver nitrate and sodium chloride
B. Silver nitrate and sodium iodide
C. Sodium hydroxide and copper(II) sulfate
D. Sodium hydroxide and iron(II) chloride

Which element is in the same group of the Periodic Table as lithium?

[Table_1]

Which properties of the element titanium, Ti, can be predicted from its position in the Periodic Table?
[Table_1]
Table Caption: Properties of the element titanium (Ti) with options A to D for predictability
| | can be used | conducts electricity | has low density | forms coloured |
| | as a catalyst | when solid | | compounds |
|----- | ----- | ----- | ----- | ----- |
| A | ✓ | ✓ | ✓ | ✗ |
| B | ✓ | ✓ | ✗ | ✓ |
| C | ✓ | ✗ | ✓ | ✓ |
| D | ✗ | ✓ | ✓ | ✓ |

The following statements are about elements in the Periodic Table.
1. Their atoms have a full outer shell of electrons.
2. They form basic oxides.
3. They are found in Group 0.
4. They are present in small quantities in the air.
Which statements are correct for the noble gases?
A 1, 2 and 3 B 1, 2 and 4 C 1, 3 and 4 D 2, 3 and 4

In the outline of the Periodic Table below, some elements are shown as numbers.



Which two numbers are metals in the same period?
A. 1 and 2    B. 1 and 7    C. 3 and 5    D. 5 and 6

Solder is an alloy of lead and tin. It is used for joining pieces of metal. Which statement about solder is correct?
A. It can be represented by a chemical formula.
B. It contains a mixture of lead and tin.
C. It contains lead and tin chemically combined.
D. It has a higher melting point than lead or tin.

What is a major use of aluminium?
A) making brass
B) making cutlery
C) making electrical wiring
D) making food containers

Which row describes the conditions used to make steel from the iron produced by a blast furnace?
[Table_1]

W, X, Y and Z are four metals.

Some properties of these metals are listed below.

1. Only W and Z can be extracted by reduction of their oxides with carbon.
2. Only X will react with cold water.
3. Only Z can be found 'native' (not combined with any other element).

What is the correct order of these metals in the reactivity series (most reactive first)?

A X, W, Y, Z
B X, Y, W, Z
C Z, W, Y, X
D Z, Y, W, X

The diagram shows stages in producing drinking water.
In which tank is chlorine added to the water?

Which gas is \textbf{not} found in clean air?
A. carbon dioxide
B. carbon monoxide
C. nitrogen
D. oxygen

Which combination of chemical compounds could be used to produce the fertiliser shown?
[Image_1: Fertiliser bag with NPK ratio 21:16:8 and label 'SUPERGROW']
A. $(NH_4)_3PO_4, KCl$
B. $NH_4NO_3, Ca_3(PO_4)_2$
C. $NH_4NO_3, CO(NH_2)_2$
D. $NH_4NO_3, K_2SO_4, (NH_4)_2SO_4$

The pollutants released into the air from car exhausts and some power stations include oxides of the type XO and YOₙ.
What are X and Y?

[Table_1]

Which statement about rusting is not correct?
A. Only oxygen is needed for rusting.
B. Painting can stop iron gates rusting.
C. Rust is hydrated iron(III) oxide.
D. Water and oxygen are both needed for rusting.

Carbon dioxide and methane are 'greenhouse gases' which contribute to global warming.
Which process does not increase global warming?
A burning fossil fuels
B decay of organic waste
C farming cattle for beef
D growing crops such as sugar cane

These statements are about a gas.
1. It is produced by thermal decomposition of a carbonate.
2. It is produced by the fermentation of glucose.
3. It makes up 1% of unpolluted air.
4. It is produced during the production of steel from iron.
Which statements are correct for carbon dioxide?
A 1 and 2 only
B 1, 2 and 3
C 1, 2 and 4
D 1, 3 and 4

The diagram represents a lime kiln.

What leaves the furnace at X?
A. calcium carbonate
B. calcium hydroxide
C. calcium oxide
D. calcium sulfate

The structures of four organic compounds are shown.

Which statement is not correct?
A. Only one of the compounds is an alcohol.
B. Only one of the compounds is an alkane.
C. Only one of the compounds is unsaturated.
D. Only three of the compounds are hydrocarbons.

Which statement about petroleum is not correct?
A. It can be separated into useful substances by fractional distillation.
B. It consists mainly of hydrocarbons.
C. It is found underground in many parts of the world.
D. Its main use is for making lubricants and polishes.

Which statement about alkane molecules is correct?
A. They burn in oxygen.
B. They contain carbon, hydrogen and oxygen atoms.
C. They contain double bonds.
D. They contain ionic bonds.

Which statements are correct for ethanoic acid?
1. It contains a carbon-oxygen double bond.
2. It contains two carbon atoms.
3. It decolourises bromine water.
4. It contains an –OH group.
A. 1 and 2 only
B. 1 and 3
C. 1, 2 and 4
D. 2, 3 and 4

A hydrocarbon A is cracked to make B and hydrogen.
Compound C is formed by the addition polymerisation of B.
To which homologous series do A, B and C belong?
[Table_1:
\begin{tabular}{|c|c|c|} \hline & \text{alkene} & \text{alkane} \\ \hline \text{A} & \text{A} & \text{B and C} \\ \text{B} & \text{B} & \text{A and C} \\ \text{C} & \text{C} & \text{A and B} \\ \text{D} & - & \text{A and C} \\ \hline \end{tabular}]

By which of the following methods is ethanol formed?
1 fractional distillation of petroleum
2 fermentation
3 catalytic addition of steam to ethene
A 1 and 2 only
B 1 and 3 only
C 2 and 3 only
D 1, 2 and 3