IGCSE Coordinated Chemistry Workout 15

In which tube does the iron nail rust in the shortest time?

• A

• B

• C

• D

Fertilisers are used to supply the essential elements needed for plant growth. Which compound supplies two of these essential elements?

• Ca(H₂PO₄)₂

• Ca(NO₃)₂

• KNO₃

• (NH₄)₂SO₄

The burning of a fuel is investigated using the apparatus shown. Which substances is the apparatus testing for?

• carbon monoxide and carbon dioxide

• carbon monoxide and water

• carbon dioxide and water

• carbon dioxide and sulfur dioxide

The diagram shows three molecules. Which molecule is a monomer and which is a polymer?

• X = monomer; Z = polymer

• Y = monomer; Z = polymer

• Y = monomer; Z = polymer

• Z = monomer; Y = polymer

Hexane and octane are liquid hydrocarbons that mix together. Which is the best method of separating a mixture of these two liquids?

• A

• B

• C

• D

What are the charge and mass of an electron?

• A

• B

• C

• D

Molten lead (II) bromide is electrolysed as shown. An element is produced at the negative electrode.

What is the name of the element and of the electrode?

• bromine at the anode

• bromine at the cathode

• lead at the anode

• lead at the cathode

Burning coal has advantages and disadvantages. Which row is correct?

• A

• B

• C

• D

Hydrochloric acid reacts with calcium carbonate. The equation for the reaction is shown.

CaCO₃ + 2HCl → CaCl₂ + CO₂ + H₂O

Which change increases the speed of the reaction?

• Decrease the temperature of the hydrochloric acid.

• Increase the concentration of the hydrochloric acid.

• Increase the size of the calcium carbonate particles.

• Increase the volume of the hydrochloric acid.

Some reactions of a substance, R, are shown in the diagram. What type of substance is R?

• an acid

• a base

• an element

• a salt