- Acid – substance that releases Hydrogen ions (H+) when it dissolves
- Base – substance that neutralises acids by removing H+ ions
- Alkali – base that releases Hydroxide ions (OH-) when it dissolves
- pH scale – the scale used to measure acidity/alkalinity
- Indicator – substance that changes colour at different pH
- Universal Indicator – indicator that has a different colour for each pH
- pH Probe – electronic device for measuring pH
- Salt – product made when an acid reacts with Metals, Metal Oxides, Metal Hydroxides or Metal Carbonates
- Chloride – salts made from Hydrochloric Acid
- Nitrate – salts made from Nitric Acid
- Sulphate – salts made from Sulphuric Acid
- Dilute – very little of a substance dissolved in a lot of water
- Concentrated – a lot of a substance dissolved in very little water
- Strong Acid – dissolves to release 100% of its H+ ions (pH usually 1 or 2) – not the same as concentrated!
- Weak Acid – dissolves to release small % of possible H+ ions (pH often 5-6) – not the same as dilute!
- Titration – accurately neutralising an alkali with and acid from a burette
