Acids, Bases and Salts are described by the pH scale (0–14).
Acids have pH less than 7 and turn litmus red; alkalis/bases have pH more than 7 and turn litmus blue; pH 7 is neutral. An acid and a base react in neutralisation to make a salt and water.
Remember
- Acid pH < 7 · Neutral pH 7 · Base pH > 7.
- Acid + base → salt + water.