IGCSE Coordinated Chemistry Workout 31

Which word equation describes the manufacture of lime from limestone?

• calcium carbonate → calcium hydroxide + carbon dioxide

• calcium carbonate → calcium oxide + carbon dioxide

• calcium hydroxide → calcium oxide + water

• calcium oxide + carbon dioxide → calcium carbonate

What is the structure of but-2-ene?

• A

• B

• C

• D

The structures of four hydrocarbons are shown. Which of the hydrocarbons change the colour of aqueous bromine?

• 1 and 2

• 1 and 3

• 2 and 4

• 3 and 4

When solid zinc carbonate is heated, a different solid and a gas are formed. Which type of change occurs?

• chemical

• exothermic

• physical

• separation

Dilute hydrochloric acid is added to aqueous sodium hydroxide in a non-insulated beaker. The temperature of the mixture increases. Which statement is not correct?

• The reaction is exothermic.

• There is a reduction in the amount of chemical energy.

• There is an increase in the amount of thermal energy.

• There is no energy loss from the mixture.

The ionic equation for the formation of chromium(III) ions is shown.

Cr → Cr³⁺ + 3e^–

Which statement about chromium atoms is correct?

• They are oxidised by gaining electrons.

• They are oxidised by losing electrons.

• They are reduced by gaining electrons.

• They are reduced by losing electrons.

Element X has two outer-shell electrons. Element Y has seven outer-shell electrons.

Which statement about X and Y is not correct?

• Element X combines with element Y to form an ionic compound.

• Element X combines with element Y to form a solid compound which conducts electricity.

• Element X conducts electricity and element Y is in Group VII of the Periodic Table.

• Element X is in Group II of the Periodic Table and element Y does not conduct electricity.

Which row describes how hydrogen and nitrogen are obtained for use in the Haber process?

• A

• B

• C

• D

Underwater pipes made from steel are prevented from rusting by sacrificial protection. Sacrificial protection uses a ..1.. reactive metal attached to the pipes which is ..2.. in

preference to the steel.

Which words complete gaps 1 and 2?

• A

• B

• C

• D

Which process is used to make ethanol?

• Addition of oxygen to ethene in the presence of a catalyst.

• Addition of oxygen to ethene with no catalyst.

• Addition of steam to ethene in the presence of a catalyst.

• Addition of steam to ethene with no catalyst.