IGCSE Coordinated Chemistry Workout 22

Some uses of alloys are shown.

Which statement about alloys is correct?

• They are always stronger than the metals from which they are made.

• They are made from metals because metals are poor electrical conductors.

• They contain mixtures of compounds that contain metals.

• They have different properties to the metals from which they are made.

The diagram shows an experiment on a liquid hydrocarbon.

Which change takes place?

• combustion

• cracking

• fractional distillation

• polymerisation

In which pair are both molecules unsaturated?

• A

• B

• C

• D

The diagram shows waste organic material decaying.

What is formed when the gas, methane, is burned?

• carbon dioxide and water

• carbon dioxide only

• carbon monoxide

• water only

The colours in an ink can be separated by chromatography.

Which diagram shows the correct way to set up the apparatus?

• A

• B

• C

• D

The positions of four elements are shown on the outline of part of the Periodic Table.

Which element forms an ion with a charge of 2+?

• A

• B

• C

• D

What are the products of the electrolysis of dilute sulfuric acid using inert electrodes?

• hydrogen and oxygen

• hydrogen and sulfur dioxide

• oxygen and sulfur

• oxygen and sulfur dioxide

Which change occurs in all exothermic reactions

• Bubbles of gas are released from the mixture.

• Light energy is produced.

• The temperature of the mixture decreases.

• The temperature of the mixture increases.

The diagram shows zinc reacting with sulfuric acid.

Which change does not increase the speed of the reaction?

• adding a catalyst

• increasing the concentration of sulfuric acid

• increasing the temperature of sulfuric acid

• reducing the surface area of zinc

Hydrogen and oxygen react explosively to form water.

Which words describe this reaction?

• A

• B

• C

• D