SPM - Strength of acids and bases

Which of the following solutions has the highest pH value?

• Ethanoic acid, 0.01 mol dm–3

• Hydrochloric acid, 0.01 mol dm–3

• Aqueous ammonia, 0.01 mol dm–3

• Sodium hydroxide solution, 0.01 mol dm–3

True or false: bases are sometimes called alkaline.

• True

• False

Ethanoic acid is a weak acid because

• it is an organic acid.

• it dissolves slightly in water.

• it is a weak conductor of electricity.

• it ionises partially to form hydrogen ions in water.

Sulphuric acid is known as a diprotic acid because

• there are two hydrogen atoms in one molecule of sulphuric acid.

• one mole of sulphuric acid contains two moles of hydrogen atoms.

• one mole of sulphuric acid dissociates into two moles of hydrogen ions in water.

• sulphuric acid can be neutralised by two types of bases.

A chemical that dissociates completely in water to produce hydroxide ions is a

• strong acid

• weak acid

• strong alkali

• weak alkali

Calculate the pH value of 0.01moldm-3 H2SO4

• 3

• 1

• 2

• 0

Which of the following statements is true of both nitric acid and sulphuric acid?

• Both are organic acids.

• Both are diprotic acids.

• Both undergo complete dissociation in water.

• Both react with copper to produce hydrogen gas.

Which of the following is true when water is added to an aqueous sodium hydroxide solution?

• The pH value decreases.

• The degree of ionisation decreases.

• The hydroxide ion concentration increases.

• The alkalinity increases.

Which of the following substances can change red litmus paper to blue when dissolved in water?

• Carbon dioxide gas

• Glacial ethanoic acid

• Solid sodium oxide

• Solid sodium sulphate

Which of the following particles in a solution of ammonia is responsible for its alkaline properties?

• NH3

• OH–

• H+

• NH4+