Cambridge IGCSE Chemistry - 0620 - Supplement Paper 2 2013 Winter Zone 1

An attempt was made to compress a gas and a solid using the apparatus shown.

Which substance would be compressed and what is the reason for this?

[Table_1]

Table 1:
| substance | reason |
|-----------|----------------------------------|
| A | gas | the gas particles are close together |
| B | gas | the gas particles are far apart |
| C | solid | the solid particles are close together |
| D | solid | the solid particles are far apart |

A student measures the rate of two reactions.
In one reaction, there is a change in mass of the reactants during the reaction.
In the second reaction, there is a change in temperature during the reaction.
Which piece of apparatus would be essential in both experiments?
A balance
B clock
C pipette
D thermometer

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.

Element X has 7 protons.
Element Y has 8 more protons than X.
Which statement about element Y is correct?
A Y has more electron shells than X.
B Y has more electrons in its outer shell than X.
C Y is in a different group of the Periodic Table from X.
D Y is in the same period of the Periodic Table as X.

Which statements about a sodium atom, $$_{11}^{23}Na$$, are correct?

1. The number of protons and neutrons is the same.
2. The number of protons and electrons is the same.
3. The number of outer electrons is one.

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

Rubidium is in Group I of the Periodic Table and bromine is in Group VII.

Rubidium reacts with bromine to form an ionic compound.

Which row shows the electron change taking place for rubidium and the correct formula of the rubidium ion?

[Table_1]

| | electron change | formula of ion formed |
|---|-----------------|-----------------------|
| A | electron gained | Rb^+ |
| B | electron gained | Rb^- |
| C | electron lost | Rb^+ |
| D | electron lost | Rb^- |

The diagrams show the electron arrangements in the atoms of four elements.
Which element does not form a covalent bond?

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]

The formulae of compounds W, X and Y are shown.
W: CuSO₄.5H₂O
X: MgSO₄.7H₂O
Y: Cu(NO₃)₂.6H₂O
Which statement is correct?
A) W contains twice as many hydrogen atoms as oxygen atoms.
B) X contains the most oxygen atoms.
C) Y contains the most hydrogen atoms.
D) Y contains the same number of hydrogen and oxygen atoms.

Which relative molecular mass, $M_r$, is not correct for the molecule given?
[Table_1: molecules and their $M_r$ values]
| molecule | $M_r$ |
| -------------- | ---- |
| A. ammonia, $\text{NH}_3$ | 17 |
| B. carbon dioxide, $\text{CO}_2$ | 44 |
| C. methane, $\text{CH}_4$ | 16 |
| D. oxygen, $\text{O}_2$ | 16 |

The diagram shows the circuit for electrolysing lead(II) bromide and sodium chloride to liberate the metal.

In what form are these salts electrolysed for liberating the metal?
[Table_1]

The diagram shows the electrolysis of concentrated aqueous sodium chloride.



What is the colour of the litmus at each electrode after five minutes?

[Table_1: colour at anode, colour at cathode]
A. blue, red
B. red, blue
C. red, colourless
D. colourless, blue

When anhydrous copper(II) sulfate is added to water a solution is formed and heat is given out.



Which row correctly shows the temperature change and the type of reaction taking place?

[Table_1]

Which fuel does not produce carbon dioxide when it burns?
A. coal
B. hydrogen
C. methane
D. petrol

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.

Anhydrous copper(II) sulfate can be made by heating hydrated copper(II) sulfate.
$$\text{CuSO}_4\cdot5\text{H}_2\text{O} \rightarrow \text{CuSO}_4 + 5\text{H}_2\text{O}$$
What can be added to anhydrous copper(II) sulfate to turn it into hydrated copper(II) sulfate?
A. concentrated sulfuric acid
B. sodium hydroxide powder
C. sulfur dioxide
D. water

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

Compound X is tested and the results are shown in the table.

[Table_1]

Which ions are present in compound X?
A. ammonium ions and carbonate ions
B. ammonium ions and chloride ions
C. calcium ions and carbonate ions
D. calcium ions and chloride ions

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 not correct?

A
Bromine
$Br_2$
Harmful liquid.
Do not spill.

B
Iodine
$I_2$
Danger
Avoid breathing vapour
from the solid.

C
Potassium
$K$
Danger
Store under water.

D
Sodium
$Na$
Danger
Store under oil.

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?
[Table_1]

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.

Some properties of four elements W, X, Y and Z are listed.
1 W melts at 1410°C and forms an acidic oxide.
2 X has a high density and is easily drawn into wires.
3 Y acts as a catalyst and its oxide reacts with acids.
4 Z is a red-brown solid used to make alloys.
Which of the elements are metals?
A 1 and 3 B 2, 3 and 4 C 2 and 3 only D 2 and 4 only

M is a shiny silver metal. It has a melting point of 1455°C. Many of its compounds are green.
What is metal M?
A. aluminium
B. copper
C. mercury
D. nickel

Reactions of three metals and their oxides are listed in the table.



What is the order of reactivity of the metals?

Equations P and Q represent two reactions which occur inside a blast furnace.

\[ \text{P } \quad \text{Fe}_2\text{O}_3 + 3\text{CO} \rightarrow 2\text{Fe} + 3\text{CO}_2 \]
\[ \text{Q } \quad \text{CaCO}_3 \rightarrow \text{CaO} + \text{CO}_2 \]
Which type of reactions are P and Q?

\[ \begin{array}{c|c|c} & ext{P} & ext{Q} \\ \hline \text{A} & \text{redox} & \text{redox} \\ \text{B} & \text{redox} & \text{thermal decomposition} \\ \text{C} & \text{thermal decomposition} & \text{redox} \\ \text{D} & \text{thermal decomposition} & \text{thermal decomposition} \\ \end{array} \]

Which row describes the uses of mild steel and stainless steel?
[Table_1]

In which process is carbon dioxide \textit{not} formed?
A. burning of natural gas
B. fermentation
C. heating lime
D. respiration

Farmers add calcium oxide (lime) and ammonium salts to their fields.
The compounds are not added at the same time because they react with each other.
Which gas is produced in this reaction?
A. ammonia
B. carbon dioxide
C. hydrogen
D. nitrogen

The diagrams show four uses of iron.
In which of these uses is the iron most likely to rust?
[Image_1: Diagrams A, B, C, D with descriptions: A) iron bucket electroplated with zinc, B) iron cored aluminium electricity cables, C) iron hinges on a gate, D) painted iron fence]

Which air pollutant is not made when coal burns in a power station?
A) carbon monoxide
B) lead compounds
C) nitrogen oxides
D) sulfur dioxide

In many countries river water is used for the washing of clothes.
The same water is not considered to be safe for drinking.
Why is it not safe for drinking?
A because river water contains dissolved salts
B because river water may contain harmful bacteria
C because river water may contain small particles of sand
D because river water may contain soap from washing clothes

The diagram shows a kiln used to heat limestone.


What is the product and what waste gas is formed?
[Table_1]

Three types of organic compound are alkanes, alkenes and alcohols.
Which structure does not belong to any of these three types of compound?

The diagram shows some properties of two organic compounds X and Y.

What are X and Y?

Petroleum is a mixture of hydrocarbons which can be separated into fractions using fractional distillation.
Which fraction is used as fuel in jet engines?

A. bitumen
B. gasoline
C. kerosene
D. naphtha

The diagram represents ethene.
[Image_1: Structural formula of ethene]
Which compound has chemical properties similar to those of ethene?
A [Image_2: Structural formula of compound A]
B [Image_3: Structural formula of compound B]
C [Image_4: Structural formula of compound C]
D [Image_5: Structural formula of compound D]

A chemist carried out a cracking reaction on a hydrocarbon, X, and obtained two products, Y and Z.

The chemist then wrote the following statements in his notebook.
1 A molecule of X has 7 carbon atoms.
2 Y is unsaturated.
3 Z will decolourise bromine water.
Which statements are correct?
A 3 only B 1 and 2 C 1 and 3 D 1, 2 and 3