What are state symbols?
- State symbols:
- show which physical state each substance is in
- are written after each formula in brackets in chemical equations
- are sometimes shown as subscript, e.g NaOH(aq)
| Solid | Liquid | Gas | Aqueous |
| (s) | (l) | (g) | (aq) |
- Aqueous should remind you of the word 'aqua' and means the substance is dissolved in water
- In other words it is a solution
- State symbols should be included when writing chemical equations.
- An example of a reaction with state symbols is the reaction of copper carbonate with hydrochloric acid:
CuCO3 (s) + 2HCl (aq) ⟶ CuCl2 (aq) + CO2 (g) + H2O (l)
Examiner Tip
Be careful when writing the state symbol of solutions of liquids. For example, ethanol, or common alcohol, is a liquid at room temperature, so if it is pure alcohol then you would be using (l) as the state symbol; most of the time alcohol is used as a solution in water so (aq) is symbol to use.
