Cambridge IGCSE Chemistry - 0620 - Core Paper 1 2014 Summer Zone 3

The diagram shows the result of dropping a purple crystal into water.



Which processes take place in this experiment?

[Table_1]

Alcohol and water are completely miscible. This means when mixed together they form only one liquid layer.
Which method is used to separate alcohol from water?

The four pieces of apparatus shown below are used in chemical experiments.
Which statement about the apparatus is correct?

The diagram shows the structure of an atom of element X.



What is X?

The ‘lead’ in a pencil is made of a mixture of graphite and clay.
When the percentage of graphite is increased, the pencil slides across the paper more easily.
Which statement explains this observation?

The diagrams show four particles.

Which two diagrams show atoms that are isotopes of each other?

Solid F is an element.
Solid G is a compound.
Neither solid conducts electricity but G conducts electricity when dissolved in water.
These properties suggest that F is ......1...... and that G is ......2...... with ......3...... bonds.
Which words correctly complete gaps 1, 2 and 3?
[Table_1]

In athletics, banned drugs such as nandrolone have been taken illegally to improve performance. Nandrolone has the molecular formula $C_{18}H_{26}O_2$. What is the relative molecular mass, $M_r$, of nandrolone? (Relative atomic mass: H = 1; C = 12; O = 16)

A compound contains one atom of calcium, two atoms of hydrogen and two atoms of oxygen.
What is the correct chemical formula of the compound?

Element X is in Group I of the Periodic Table. X reacts with element Y to form an ionic compound. Which equation shows the process that takes place when X forms ions?

Which substance will not conduct electricity?

Two chemical processes are described below.
● In the combustion of methane, energy is ......1...... .
● In the electrolysis of molten lead(II) bromide, energy is ......2...... .
Which words correctly complete gaps 1 and 2?

Which equation shows an oxidation reaction?

Some reactions are endothermic. How does the temperature and energy change in an endothermic reaction? [Table_1]

Which products are formed at the anode and cathode when electricity is passed through molten lead(II) bromide?
[Table_1]

An experiment is carried out to investigate the rate of reaction when calcium carbonate is reacted with hydrochloric acid. The volume of carbon dioxide gas given off is measured at different intervals of time.
The diagram shows pieces of apparatus used to collect gases.
Which apparatus is suitable to collect and measure the volume of the carbon dioxide?

In separate experiments, a catalyst is added to a reaction mixture and the temperature of the mixture is decreased.
What are the effects of these changes on the rate of the reaction?
[Table_1]

Which statements about alkalis are correct?
1. When reacted with an acid, the pH of the alkali increases.
2. When tested with litmus, the litmus turns blue.
3. When warmed with an ammonium salt, ammonia gas is given off.

Which acid reacts with ammonia to produce the salt ammonium sulfate?

The equation shows a reaction that is reversed by changing the conditions.
forward reaction
$$\text{CuSO}_4 . 5\text{H}_2\text{O} \rightarrow \text{CuSO}_4 + 5\text{H}_2\text{O}$$
How can the forward reaction be reversed?
[Table: by adding water, by heating]

Only two elements are liquid at 20°C. One of these elements is shiny and conducts electricity.
This suggests that this element is a ......1...... and therefore its oxide is ......2...... .
Which words correctly complete gaps 1 and 2?

An element melts at 1455°C, has a density of 8.90 g/cm$^3$ and forms a green chloride.
Where in the Periodic Table is this element found?

Why is argon gas used to fill electric lamps?

Which statement about the Periodic Table is correct?

Aqueous sodium hydroxide is added to solid X and the mixture is heated.
A green precipitate is formed and an alkaline gas is given off.
Which ions are present in X?

In an experiment, three test-tubes labelled X, Y and Z were half-filled with dilute hydrochloric acid. A different metal was added to each test-tube. After a few minutes the following observations were made.
In tube X, bubbles slowly rose to the surface.
In tube Y, there was a rapid release of bubbles.
In tube Z, no bubbles were produced.
Which three metals match the observations?
[Table_1]

The diagrams show two items that may be found in the home. Each item contains zinc.
[Image_1: Zinc plated bucket and brass door-knocker]
In which is zinc used as an alloy?
[Table_1: Options for bucket and door-knocker]

The diagram shows some uses of water in the home.

For which uses is it important for the water to have been treated?

The table shows properties of four metals.
Which metal is the most suitable for aircraft construction?
[Table_1]

The diagram shows a blast furnace. In which part is iron ore changed to iron?

Acid rain is formed when sulfur dioxide and oxides of nitrogen dissolve in rain water.
Which problem is not caused by acid rain?

Which compound contains two of the three essential elements needed for a complete fertiliser?

Four steel paper clips are treated as described before being placed in a beaker of water.
Which paper clip rusts most quickly?

When compound X is heated, it changes colour from green to black. Compound Y is formed and a gas is given off which turns limewater milky.

What are X and Y?
[Table_1]

Which type of compound is shown?

The table shows the composition of four different types of petroleum (crude oil).
[Table showing the composition of petroleum]
Which type of petroleum is best for the motor vehicle industry?

Which pollutant gas is produced by the decomposition of vegetation?

X, Y and Z are three hydrocarbons.
X \,\,\, \text{CH}_2=\text{CH}_2 \quad \quad Y \,\,\, \text{CH}_3-\text{CH}=\text{CH}_2 \quad \quad Z \,\,\, \text{CH}_3-\text{CH}_2-\text{CH}=\text{CH}_2
What do compounds X, Y and Z have in common?
1. They are all alkenes.
2. They are all part of the same homologous series.
3. They all have the same boiling point.

Alkenes are manufactured by cracking hydrocarbons obtained from petroleum.
[Image_1: alkane X obtained from petroleum → cracking → alkene Y]
Which row describes the process of cracking?
[Table_1: size of X molecules | size of Y molecules | catalyst required | temperature required]

Which statements about ethanol are correct?
1. It can be made by fermentation.
2. It is an unsaturated compound.
3. It burns in air and can be used as a fuel.