What a base is

Look back at assignment 7.1: milk of magnesia, toothpaste, soap and slaked lime are bases.

Most bases are solids; ammonia is a gas with basic properties. In the laboratory they are used as solutions in water. Common laboratory bases are sodium hydroxide (NaOH), potassium hydroxide (KOH) and ammonia solution (NH₄OH).

Figure to be added

Figure 7.3 — containers of sodium hydroxide, potassium hydroxide and milk of magnesia.

Base

A base is a chemical compound that raises the concentration of hydroxyl ions (OH^-) in an aqueous solution.

Sodium hydroxide ionises in water and raises the OH^- concentration:

NaOH (aq) → Na⁺ (aq) + OH^- (aq)