Cambridge IGCSE Chemistry - 0620 - Core Paper 1 2020 Summer Zone 1

Nitrogen is heated in a balloon, which expands slightly. Which statements about the molecules of nitrogen are correct?
1. They move further apart.
2. They move more quickly.
3. They remain the same distance apart.
4. Their speed remains unchanged.

Which piece of apparatus should be used to measure exactly 21.4 \text{ cm}^3 of water?

Which method of separation is used to separate a soluble solid from its solution?

The atomic number and nucleon number of a potassium atom are shown.

[Table_1]
atomic number: 19
nucleon number: 39

How many protons, neutrons and electrons are in a potassium ion, K⁺?

Sodium is in Group I of the Periodic Table.
Chlorine is in Group VII of the Periodic Table.
Sodium and chlorine combine to form a compound.
Which statement about the combination of sodium and chlorine atoms is correct?

The electronic structures of two atoms, P and Q, are shown.
P and Q combine together to form a compound. What is the type of bonding in the compound and what is the formula of the compound?

The structures of diamond and graphite are shown.
Which statement about diamond and graphite is correct?

Aluminium oxide has the formula $\text{Al}_2\text{O}_3$.
Which statement about aluminium oxide is correct?

Which products are formed when dilute sulfuric acid undergoes electrolysis? [Table_1]

Which element is not used as a fuel?

The energy level diagram shows the energy of the reactants and products in a chemical reaction.

Which row correctly describes the energy change and the type of reaction shown?

Which diagram represents a chemical change?

The rate of reaction between magnesium and hydrochloric acid is investigated. The volume of hydrogen given off at different times is measured. The results are shown.
Which conclusions are correct?
1. The rate is fastest between 0 and 20 seconds.
2. The maximum volume of hydrogen given off is 22 cm³.
3. At 40 seconds, 20 cm³ of hydrogen is given off.

Which reaction can be easily reversed?

Carbon reacts with silver oxide to form carbon dioxide and silver. Which substance is reduced?

The graph shows how the pH of a solution changes as an acid is added to an alkali.
acid + alkali → salt + water
Which letter represents the area of the graph where both acid and salt are present?

Phosphorus is an element in Group V of the Periodic Table.
It burns in air to form an oxide, which dissolves in water to form a solution with a pH of 1.
Which row describes this oxide of phosphorus?
[Table_1: metal oxide, non-metal oxide, acidic oxide, basic oxide]
A. ✓ ✗ ✓ ✗
B. ✓ ✗ ✗ ✓
C. ✗ ✓ ✓ ✗
D. ✗ ✓ ✗ ✓

The apparatus shown is used to prepare aqueous copper(II) sulfate.


What are X and Y?

Two tests are carried out on substance Z.

test 1   A flame test produces a red flame.

test 2   Z is dissolved in water and dilute nitric acid is added, followed by aqueous silver nitrate. A yellow precipitate is produced.

What is substance Z?

The elements in Period 3 of the Periodic Table are shown.
[Table_1: Na, Mg, Al, Si, P, S, Cl, Ar]
Which statements about the elements in Period 3 are correct?
1. Na, Mg and Al are metals.
2. S, Cl and Ar are non-metals.
3. Si, P and S are metals.

A Group I metal (lithium, sodium or potassium) is reacted with a Group VII element (chlorine, bromine or iodine). Which compound is formed when the Group I metal of highest density reacts with the Group VII element of lowest density?

The properties of the element titanium, Ti, can be predicted from its position in the Periodic Table.
Which row identifies the properties of titanium?
[Table_1]

A balloon is filled with helium. Helium is a noble gas and makes the balloon rise up in the air. The density of air is 1.23 g/dm$^3$.
Which gas is helium?
[Table_1]

Which property is shown by all metals?

The properties of four metals, W, X, Y, and Z, are shown.

W It does not react with cold water but reacts with steam.
X It does not react with water or dilute acid but the oxide of X is reduced by carbon.
Y The oxide of Y is not reduced by carbon but Y reacts vigorously with cold water.
Z It does not react with water or steam but reacts with dilute acid.

What is the order of reactivity of the elements starting with the most reactive?

[Table_1]
| most reactive | -> | least reactive |
|---|---|---|---|
| A | X | W | Z | Y |
| B | X | Z | W | Y |
| C | Y | W | Z | X |
| D | Y | Z | W | X |

Molten iron from the blast furnace contains impurities. The process of turning the impure iron into steel involves blowing oxygen into the molten iron and adding calcium oxide. What are the reasons for blowing in oxygen and adding calcium oxide? [Table_1]

Which row describes two uses of the named steel?
[Table_1]

Which statement shows that a liquid is pure water?

Some gases are present in clean air while other gases are only present in polluted air.
Which row is correct?
[Table_1]

The diagrams show experiments to investigate rusting of iron nails.
In which test-tubes do the nails rust?

Which mixture contains all of the elements in a typical fertiliser?

Which processes produce methane?
1. complete combustion of carbon-containing compounds
2. decomposition of vegetation
3. digestion in animals
4. respiration in animals

The list shows four methods that were suggested for the formation of carbon dioxide.
1. cracking methane using steam
2. action of heat on a carbonate
3. complete combustion of methane
4. reaction of a carbonate with oxygen
Which methods would result in the production of carbon dioxide?

A student suggests three uses of calcium carbonate (limestone).

1. manufacture of cement
2. manufacture of iron
3. treating alkaline soils

Which suggestions are correct?

Which list shows the fractions obtained from distilling petroleum, in order of increasing boiling point?

Which statement about members of a homologous series is correct?

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 showing hydrocarbons in different energy release orders]

Which statements about ethanol are correct?
1. Ethanol is made by reacting steam with ethene at 300°C.
2. Ethanol is made by fermentation at 55°C.
3. Ethanol burns to produce carbon dioxide and water.
4. Ethanol contains a carbon-carbon double bond.

Some properties of an organic compound J are listed.
• It is a liquid at room temperature.
• It is soluble in water.
• A solution of J reacts with calcium carbonate to form carbon dioxide.
• A solution of J has a pH of 3.

In which homologous series does J belong?

Which polymers or types of polymer are synthetic?

1 carbohydrates
2 nylon
3 proteins
4 \textit{Terylene}