Reactions of Acids

What is an acid in terms of pH?

A solution with a pH of less than 7.

What is a neutral solution in terms of pH?

A solution with a pH of 7.

What is an acid in terms of H+ ions?

A substance that releases H+ ions when dissolved in water.

How is the amount of H+ ions in a solution related to its pH?

The more H+ ions, the lower the pH.

What are the names and formulae of three main acids?

Hydrochloric acid (HCl), sulfuric acid (H₂SO₄), nitric acid (HNO₃).

How do you measure the pH of a substance?

Using a universal indicator or pH probe.

What is a strong acid?

An acid where the molecules or ions completely ionise in water.

What is a weak acid?

An acid where the molecules or ions partially ionise in water.

What is a salt?

A compound formed when a metal ion takes the place of a hydrogen ion in an acid.

Which type of salts do sulfuric acid, hydrochloric acid, and nitric acid form?

Sulfates, chlorides, nitrates.

What are the products of a reaction between a metal and an acid?

Salt + hydrogen.

What are the products of a reaction between a metal hydroxide and an acid?

Salt + water.

What are the products of a reaction between a metal oxide and an acid?

Salt + water.

What are the products of a reaction between a metal carbonate and an acid?

Salt + water + carbon dioxide.

What is a base?

A substance that reacts with acids in neutralisation reactions.

What is an alkali?

A substance that dissolves in water to form a solution above pH 7.

What is a neutralisation reaction?

A reaction between an acid and a base to produce water.

What is the ionic equation for a reaction between an acid and an alkali?

H+(aq) + OH-(aq) → H₂O(l).

How can you obtain a solid salt from a solution?

Through crystallisation.

When an acid reacts with a metal, which species is oxidised?

The metal.

When an acid reacts with a metal, which species is reduced?

Hydrogen.