Chemistry Revision Unit 1 - 11

A crystal of purple potassium manganate (VII) was added to each of the beakers shown in the diagram.

• A

• B

• C

• D

During a reaction, the following changes take place.

1 The temperature rises.

2 A gas is given off.

Which apparatus is required to measure the rate of this reaction?

• balance and burette

• balance and gas syringe

• gas syringe and burette

• gas syringe and stopclock

Which statement about bonding is not correct?

• Carbon can form four single covalent bonds.

• Chlorine atoms react to gain a noble gas electronic structure.

• Covalent bonding involves losing and gaining electrons.

• Hydrogen molecules have the formula H2.

The table shows the numbers of particles present in the nuclei of four atoms or ions. Which two particles belong to the same element?

• 1 and 2

• 1 and 4

• 2 and 3

• 2 and 4

Which substance is an ionic compound?

• A

• B

• C

• D

Covalent bonds are formed when electrons are ……1…… . Most covalent compounds have ……2…… electrical conductivity. Which words correctly complete gaps 1 and 2?

• A

• B

• C

• D

Which equation for the reaction between sodium carbonate and dilute hydrochloric acid is correct?

• A

• B

• C

• D

The diagram shows apparatus for plating a spoon with silver. Which statement is not correct?

• Silver would stick to the spoon because it is a very reactive metal.

• The electrolyte would be a silver salt dissolved in water.

• The metal electrode would be made from silver.

• The spoon would be connected to the negative terminal of the power supply.

Which equation for the reaction between sodium carbonate and dilute hydrochloric acid is correct?

• Na₂CO₃(s) + HCl(aq) → NaCl(aq) + CO₂(g) + H₂O(I)

• Na₂CO₃(s) + HCl(aq) → Na₂Cl(aq) + CO₂(g) + H₂O(I)

• Na₂CO₃(s) + 2HCl(aq) → NaCl(aq) + CO₂(g) + H₂O(I)

• Na₂CO₃(s) + 2HCl(aq) → 2NaCl(aq) + CO₂(g) + H₂O(I)

A student investigates the rate of reaction between marble chips and hydrochloric acid. The mass of the reaction flask is measured. The graph shows the results of two experiments, P and Q. Which change explains the difference between P and Q?

• A catalyst is added in P.

• A higher temperature is used in P.

• Bigger marble chips are used in Q.

• Hydrochloric acid is more concentrated in Q.