IGCSE Coordinated Chemistry Workout 26

W, X, Y and Z are diagrams representing atoms and molecules.

• W and Z are molecules and X and Y are atoms.

• W, X and Z are molecules and Y is an atom.

• W, Y and Z are molecules and X is an atom.

• X, Y and Z are molecules and W is an atom.

Hexane and octane are liquid hydrocarbons that mix together.

Which apparatus is used to separate a mixture of these two liquids?

• A

• B

• C

• D

Which dot-and-cross diagram represents the bonding of electrons in a molecule of ethene?

• A

• B

• C

• D

Hydrogen chloride is a gas. It dissolves in water to form an acidic solution.

Three different samples of hydrogen chloride are listed.

1. 73.0 g of hydrogen chloride gas

2. 7.30 dm³ of hydrogen chloride gas

3. 730 cm³ of 1.00 mol / dm³ solution of hydrogen chloride

Which row shows the relative number of moles of hydrogen chloride in these samples?

• A

• B

• C

• D

Which statement describes what happens during electrolysis?

• Covalent compounds produce more complex substances.

• Covalent compounds produce simpler substances.

• Ionic compounds produce more complex substances.

• Ionic compounds produce simpler substances.

Methane is used as a fuel.

Which row describes the temperature change and the type of reaction when methane burns?

• A

• B

• C

• D

Which word equation represents a redox reaction?

• calcium carbonate → calcium oxide + carbon dioxide

• calcium oxide + hydrochloric acid → calcium chloride + water

• copper oxide + carbon → copper + carbon dioxide

• sodium oxide + water → sodium hydroxide

The electronic structures of four particles are shown.

Which diagrams represent the electronic structures of a Group VI atom and its ion?

• 1 and 2

• 1 and 4

• 2 and 3

• 3 and 4

Part of the reactivity series is shown.

Which method is used to extract potassium from its ore?

• electrolysis of the molten ore

• electrolysis of the ore dissolved in water

• heating the ore with hydrogen

• heating the ore with carbon

Which row describes the source of hydrogen and of nitrogen used to manufacture ammonia in the Haber process?

• A

• B

• C

• D