An acid-base indicator is a substance that changes color as the pH of the solution changes. Indicators work because they are weak acids which when in solution, exist in equilibrium with their ...

A neutralisation reaction is one in which an acid reacts with a base to form water. A salt is also formed in this reaction. Bases are metal oxides, metal hydroxides and metal carbonates.

All alkaline solutions contain more hydroxide ions than hydrogen ions. Adding water to an acid or base will change its pH. Water is mostly water molecules so adding water to an acid or base ...