Cambridge IGCSE Chemistry - 0620 - Supplement Paper 2 2014 Winter Zone 2

Ethanol is made by fermentation.
How is ethanol obtained from the fermentation mixture?
A chromatography
B crystallisation
C electrolysis
D fractional distillation

Which statement is an example of diffusion?
A. A kitchen towel soaks up some spilt milk.
B. Ice cream melts in a warm room.
C. Pollen from flowers is blown by the wind.
D. The smell of cooking spreads through a house.

A mixture is separated using the apparatus shown. What is the mixture?
A. aqueous copper chloride and copper
B. aqueous copper chloride and sodium chloride
C. ethane and methane
D. ethanol and water

What is different for isotopes of the same element?
A nucleon number
B number of electron shells
C number of electrons in the outer shell
D proton number

Slate has a layered structure and can easily be split into thin sheets. Which diagram shows a structure most like that of slate? [Image_A], [Image_B], [Image_C], [Image_D]

Sodium chloride is an ionic solid.
Which statement is not correct?
A. Ions are formed when atoms lose or gain electrons.
B. Ions in sodium chloride are strongly held together.
C. Ions with the same charge attract each other.
D. Sodium chloride solution can conduct electricity.

Caesium chloride and rubidium bromide are halide compounds of Group I elements.

Caesium chloride has the formula ......1......, a relative formula mass ......2...... that of rubidium bromide and bonds that are ......3...... .

Which words correctly complete gaps 1, 2 and 3?

[Table_1:
| | 1 | 2 | 3 |
|---|-----|----------------|-------|
| A | CaCl | different from | ionic |
| B | CaCl | the same as | covalent |
| C | CsCl | different from | ionic |
| D | CsCl | the same as | covalent | ]

Which element has the atomic structure shown?



Key:
● e - electron
● n - neutron
● (dashed circle) - nucleus

Options:
A. Al
B. P
C. S
D. Si

How many atoms of hydrogen are there in a molecule of ethanol, $C_2H_5OH$?
A 1 B 2 C 5 D 6

Which metal could not be used for electroplating by using an aqueous solution?
A. chromium
B. copper
C. silver
D. sodium

Which products are formed at the electrodes when a concentrated solution of sodium chloride is electrolysed?
[Table_1]

Iron forms an oxide with the formula $Fe_2O_3$.
What is the relative formula mass of this compound?
A 76
B 100
C 136
D 160

Which statements about exothermic and endothermic reactions are correct?
1. During an exothermic reaction, heat is given out.
2. The temperature of an endothermic reaction goes up because heat is taken in.
3. Burning methane in the air is an exothermic reaction.
A. 1, 2 and 3
B. 1 and 2 only
C. 1 and 3 only
D. 2 and 3 only

A power station was designed to burn gaseous fuels only.
Which two substances could be used?
A. carbon dioxide and hydrogen
B. carbon dioxide and $^{235}U$
C. hydrogen and methane
D. methane and $^{235}U$

The diagram shows the change from an anhydrous salt to its hydrated form. [Image_1: Diagram showing anhydrous salt <=> hydrated salt, with forward and reverse labels]
Which statement is correct?
A. forward reaction requires heat and water
B. forward reaction requires water only
C. reverse reaction requires heat and water
D. reverse reaction requires water only

The rate of a reaction depends on temperature, concentration, particle size and catalysts.
Which statement is not correct?
A. Catalysts can be used to increase the rate of reaction.
B. Higher concentration decreases the rate of reaction.
C. Higher temperature increases the rate of reaction.
D. Larger particle size decreases the rate of reaction.

Which changes decrease the rate of reaction between magnesium and air?
1. heating the magnesium to a higher temperature
2. using a higher proportion of oxygen in the air
3. using magnesium ribbon instead of powdered magnesium
A 1, 2 and 3 B 1 only C 2 only D 3 only

Which substance is the most acidic?
[Table_1]
| substance | pH |
| --- | --- |
| A | calcium hydroxide | 12 |
| B | lemon juice | 4 |
| C | milk | 6 |
| D | washing up liquid | 8 |

The equations for two reactions P and Q are given.

P \(\textbf{2NaNO}_2 + \text{O}_2 \rightarrow \text{2NaNO}_3\)
Q \(\textbf{2HgO} \rightarrow \text{2Hg} + \text{O}_2\)

In which of these reactions does oxidation of the underlined substance occur?

[Table_1]

The positions of elements W, X, Y and Z in the Periodic Table are shown.
Which elements form basic oxides?
A. W, X and Y
B. W and X only
C. Y only
D. Z only

How many different salts could be made from a supply of dilute sulfuric acid, dilute hydrochloric acid, copper, magnesium oxide and zinc carbonate?
A 3
B 4
C 5
D 6

Elements in Group I of the Periodic Table react with water. Which row describes the products made in the reaction and the trend in reactivity of the elements?
[Table_1]

The graph shows how the pH of soil in a field changes over time.
At which point was the soil neutral?

The table shows the reactions of four different metals with water.

[Table_1]

metal         reaction
W        reacts vigorously with cold water
X        no reaction with water
Y        reacts very slowly with water, more vigorously with steam
Z        reacts violently with cold water

What is the correct order of reactivity, from most reactive to least reactive?

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

An inert gas X is used to fill weather balloons.
Which descriptions of X are correct?

[Table_1]

Table:
| | number of outer electrons in atoms of X | structure of gas X |
|---|---------------------------------------|-----------------------|
| A | 2 | single atoms |
| B | 2 | diatomic molecules |
| C | 8 | single atoms |
| D | 8 | diatomic molecules |

An element X has the two properties listed.
1. It acts as a catalyst.
2. It forms colourless ions.
Which of these properties suggest that X is a transition element?

[Table_1]

The oxide of element X is reduced by heating with carbon.
Element X does not react with cold water, steam or dilute hydrochloric acid.
What is X?
A. copper
B. iron
C. magnesium
D. zinc

Which information about an element can be used to predict its chemical properties?
A) boiling point
B) density
C) melting point
D) position in the Periodic Table

Aluminium is the most common metal in the Earth's crust.
Which is not a property of aluminium?
A low density
B resistance to corrosion
C good conductor of electricity
D poor conductor of heat

Which reaction involves oxidation?
A. heating hydrated copper(II) sulfate in the air
B. polymerisation of ethene
C. rusting of iron
D. thermal decomposition of calcium carbonate

Which object is least likely to contain aluminium?
A. a bicycle frame
B. a hammer
C. a saucepan
D. an aeroplane body

Which method can be used to obtain ammonia from ammonium sulfate?
A. Heat it with an acid.
B. Heat it with an alkali.
C. Heat it with an oxidising agent.
D. Heat it with a reducing agent.

Which is an air pollutant that affects a part of the body other than the lungs and blood system?
A. lead compounds
B. nitrogen
C. oxides of nitrogen
D. sulfur dioxide

Which statement about methane is \textit{not} correct?
A. It is a liquid produced by distilling petroleum.
B. It is produced as vegetation decomposes.
C. It is produced by animals, such as cows.
D. It is used as a fuel.

Which method of purification would produce water most suitable for drinking?
[Image_1: Diagram showing different methods of purification from muddy river water to purified water, labeled A to D]

Which molecular structure shows hexene?

Increasing the number of atoms in one molecule of a hydrocarbon increases the amount of energy released when it burns.
What is the correct order?
[Table]

Which statement about alkenes is not correct?
A The functional group is C=C.
B The structural difference between one member and the next is –CH₃–.
C They form a homologous series.
D They turn aqueous bromine from brown to colourless.

The diagram shows three repeat units in the structure of an addition polymer.

Which alkene monomer is used to make this polymer?
A)
B)
C)
D)

Ethanol can be manufactured from substance X.

$\text{substance X + steam} \xrightarrow{catalyst} \text{ethanol}$

What is substance X?

A. carbon dioxide
B. ethene
C. hydrogen
D. oxygen