Cambridge IGCSE Chemistry - 0620 - Supplement Paper 2 2013 Winter Zone 3

A gas jar of bromine vapour and a gas jar of air are set up as shown in diagram 1. The glass slide is removed. Diagram 2 shows the appearance of the gas jars after one hour.
[Image: Diagram showing bromine and air mixing]
Which statement explains why the bromine and air mix together?
A) Bromine is denser than air.
B) Bromine is lighter than air.
C) Bromine molecules moved upwards and molecules in air moved downwards.
D) Molecules in bromine and air moved randomly.

The diagram shows a method for separating a substance that contains X and Y.
Which types of substance can be separated as shown?
A compounds
B elements
C mixtures
D molecules

Diagram 1 shows the paper chromatogram of substance X.
Diagram 2 shows the cooling curve for substance Y.
Which statement about X and Y is correct?
A. X is a mixture and Y is a pure substance.
B. X is a pure substance and Y is a mixture.
C. X and Y are mixtures.
D. X and Y are pure substances.

The atomic structures of four atoms are shown.

[Table_1]

Which pair of atoms are isotopes?
A W and X
B W and Y
C X and Y
D Y and Z

The diagram shows the structure of three particles, R, S, and T.
[Image_1: Diagram of particles R, S, and T]
Key:
e = electron
n = neutron
p = proton
dotted circle = nucleus
Which row describes these particles?

[Table_1]
| | ions | isotopes |
|-----|-------|-----------|
| A | R | S and T |
| B | R and S | T |
| C | S | R and T |
| D | T | R and S |

Which statement about the bonding in a molecule of water is not correct?
A. Both hydrogen and oxygen have a noble gas configuration of electrons.
B. Each hydrogen shares its one electron with oxygen.
C. Oxygen shares one of its own electrons with each hydrogen.
D. Oxygen shares two of its own electrons with each hydrogen.

The electronic structures of atoms P and Q are shown. P and Q react to form an ionic compound. What is the formula of the compound? A Q_7P B QP C QP_3 D QP_7

A solid mixture contains an ionic salt, X, and a covalent organic compound, Y.
Two students suggest methods of separating the mixture as shown.

Which methods of separation are likely to work?
[Table_1]

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

Two electrolysis experiments were carried out as shown in the diagram below.
The graphite electrodes are labelled 1-4.



Which row describes the products at the electrodes in these experiments?

[Table_1]

One molten compound and two aqueous solutions were electrolysed. The table gives the compounds electrolysed and the electrodes used.

[Table_1]

In which experiments is a gas evolved at the cathode?
A 1, 2 and 3
B 1 and 2 only
C 1 only
D 3 only

When ammonium nitrate is added to water the temperature of the water decreases. The ammonium nitrate can be recovered by evaporating the water added. Which explains these observations?
A The ammonium nitrate dissolves in the water and the process is endothermic.
B The ammonium nitrate reacts with the water and the process is endothermic.
C The ammonium nitrate dissolves in the water and the process is exothermic.
D The ammonium nitrate reacts with the water and the process is exothermic.

Which substance could not be used as a fuel to heat water in a boiler?
A. ethanol
B. hydrogen
C. methane
D. oxygen

Which substance is not a fossil fuel?
A. coal
B. kerosene
C. gasoline
D. wood

A student investigates the rate of reaction between zinc and an excess of sulfuric acid. The graph shows the results of two experiments, X and Y.

Which change explains the difference between X and Y?
A A catalyst is added in Y.
B A lower temperature is used in Y.
C Larger pieces of zinc are used in Y.
D Less concentrated acid is used in Y.

When green iron(II) sulfate is heated, it turns white and a colourless liquid is produced. When the liquid is put back into the white solid it changes back to green. What type of reaction takes place and what is the name of the liquid?

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

[Table_1]

Which are properties of an acid?

1. reacts with ammonium sulfate to form ammonia
2. turns red litmus blue

[Table_1]

Which of the following are properties of the oxides of non-metals?
[Table_1]

[Table_1]:
| | property 1 | property 2 |
|---|-----------|------------|
| A | acidic | covalent |
| B | acidic | ionic |
| C | basic | covalent |
| D | basic | ionic |

The cations shown are identified by the colour of the precipitates formed when an excess of an aqueous solution of X is added.

[Table_1]

cations present | effect of adding an excess of aqueous X
--------------------------------------------------------
iron(II) ($Fe^{2+}$) | green precipitate
copper(II) ($Cu^{2+}$) | light blue precipitate
iron(III) ($Fe^{3+}$) | red-brown precipitate

What is X?

A ammonia
B limewater
C silver nitrate
D sodium hydroxide

Calcium, on the left of Period 4 of the Periodic Table, is more metallic than bromine on the right of this period.
Why is this?
Calcium has
A fewer electrons.
B fewer protons.
C fewer full shells of electrons.
D fewer outer shell electrons.

The diagrams show the labels of four bottles.
Which label is \textit{not} correct?

An element has a melting point of 1084°C and a density of 8.93 g/cm³. Its oxide can be used as a catalyst. In which position in the Periodic Table is the element found? [Image_1: Diagram of Periodic Table with positions labeled A, B, C, D]

The diagram shows a light bulb.
Why is argon used instead of air in the light bulb?
A. Argon is a good conductor of electricity.
B. Argon is more reactive than air.
C. The filament glows more brightly.
D. The filament does not react with the argon.

Duralumin is an alloy. It contains aluminium, copper and magnesium.
It has many uses including the manufacture of cooking utensils and ships.
Which statement about duralumin and its properties is correct?
A It is a good conductor of electricity.
B It is brittle.
C It is soluble in water.
D The aluminium, copper and magnesium are chemically combined.

The list gives the order of some metals (and hydrogen) in the reactivity series.
Metal X is also included:

Most reactive           K
                                                Mg
                                                Zn
                            (H)
                                                               X
Least reactive        Cu

Which row correctly shows the properties of metal X?

[Table_1]

A new bicycle is being developed. Two different materials are used in its construction, both of which must be corrosion resistant. [Image_1: Bicycle] Which two metals could be used? A. aluminium and mild steel B. aluminium and stainless steel C. mild steel and pure iron D. pure iron and stainless steel

Iron is extracted from hematite in the Blast Furnace.



The hematite contains silica as an impurity. What reacts with this impurity to remove it?
A. calcium oxide
B. carbon
C. carbon dioxide
D. oxygen

Iron is extracted from hematite in the Blast Furnace.

The hematite contains silica as an impurity.
What reacts with this impurity to remove it?
A calcium oxide
B carbon
C carbon dioxide
D oxygen

Carbon dioxide is produced when
X reacts with ethanol.
Y reacts with sodium carbonate.
What are X and Y?
[Table_1]

[Table_1]:
| | X | Y |
|---|----|------|
| A | H₂ | HCl |
| B | H₂ | NaOH |
| C | O₂ | HCl |
| D | O₂ | NaOH |

A sample of fertiliser is tested by warming it with aqueous sodium hydroxide.
A colourless gas is produced which turns red litmus paper blue.
Which element, essential for plant growth, must be present?
A nitrogen
B phosphorus
C potassium
D sulfur

Iron rusts. This process involves the ......1...... of iron. Rusting can be prevented by covering the iron with grease or paint which stops ......2...... from reaching the surface of the iron.
Which words correctly complete gaps 1 and 2?
[Table_1]

Oxides of nitrogen are given out from car exhausts.
Which row best shows why oxides of nitrogen are unwanted?

| | acidic | toxic |
|---|--------|-------|
| A | no | no |
| B | no | yes |
| C | yes | no |
| D | yes | yes |

Water is treated at a water works to make it fit to drink.
What is present in the water when it leaves the waterworks?
A. bacteria only
B. bacteria and insoluble substances
C. chlorine only
D. chlorine and soluble substances

The diagram shows a kiln used to heat limestone.



What is the product and what waste gas is formed?

[Table_1]

| | product | waste gas |
|:---:|:----------------:|:--------------:|
| A | lime, CaO | carbon monoxide|
| B | lime, CaO | carbon dioxide |
| C | slaked lime, Ca(OH)$_2$ | carbon monoxide|
| D | slaked lime, Ca(OH)$_2$ | carbon dioxide |

Molecule X is both an alkene and a carboxylic acid.
Which row describes X?
[Table_1]
---
saturated | –COOH present
A no | no
B no | yes
C yes | no
D yes | yes

Which hydrocarbon reacts with steam to produce ethanol?
A) $C_2H_4$
B) $C_2H_6$
C) $C_3H_6$
D) $C_3H_8$

Petroleum is a mixture of different hydrocarbons.
Which process is used to separate the petroleum into groups of similar hydrocarbons?
A combustion
B cracking
C fractional distillation
D reduction

Which row represents compounds in the same homologous series?

A


B


C


D

The diagram shows a flow diagram.

Which type of organic compounds are X and Y?