IGCSE Coordinated Chemistry Workout 20

A pupil wants to find out if the reaction of 25 cm³ of an acid with 25 cm³ of an alkali is exothermic.

Which two pieces of apparatus are needed?

• balance and measuring cylinder

• Bunsen burner and measuring cylinder

• Bunsen burner and thermometer

• thermometer and measuring cylinder

Some white anhydrous copper(II) sulfate powder is put into a beaker of water and stirred.

Which observation shows that the process is exothermic?

• A blue solution forms.

• A colourless solution forms.

• The beaker feels cooler.

• The beaker feels warmer.

Marble (calcium carbonate) reacts with dilute hydrochloric acid. 1 g of powdered marble reacts faster with the same volume and concentration of acid than a 1 g lump of marble.

What is the reason for this observation?

• The powder has a larger mass.

• The powder has a larger surface area.

• The powder has a smaller mass.

• The powder has a smaller surface area.

The Group 1 alkali metals become more reactive going down the group.

Which statement does not explain this?

• The atomic radius increases.

• The valence electrons are less attracted by the nucleus.

• More energy is required to remove the valence electron.

• There are more electron shells between the valence electron and the nucleus.

When iron is heated with steam a black solid is formed. The equation for the reaction is shown:

3Fe + 4H₂O → Fe₃O₄ + 4H₂

Which statement is correct for this reaction?

• Iron has been oxidised because it has gained oxygen.

• Iron has been reduced because it removed oxygen from water.

• Iron oxide has been reduced because it contains oxygen.

• Water has been oxidised because it contains oxygen.

Hydrochloric acid is added to calcium carbonate. Gas X, which turns limewater milky, is given off.

What is X?

• chlorine

• carbon dioxide

• hydrogen

• oxygen

Which row describes an element on the left of the Periodic Table and its oxide?

• A

• B

• C

• D

Which Group I metal and which Group VII non-metal react together most vigorously?

• A

• B

• C

• D

Calcium carbonate, CaCO₃, is decomposed by heating in an industrial process as shown:

CaCO_3(s) → CaO_(s) + CO_2(g)

Which statement is not correct?

• The common name for calcium carbonate is limestone.

• The common name for CaO is lime.

• CaO is used to neutralise alkaline soil.

• CaO is used to neutralise industrial waste products.

An alkane molecule undergoes the chemical change as shown.

What is the name of the chemical change?

• cracking

• fractional distillation

• polymerisation

• reduction