Common acids

1. Definition of Acids

✔ Acids are substances that release $H^+$ (hydrogen ions) or $H_3O^+$ (hydronium ions) in water.

✔ They have a sour taste and are corrosive.

✔ Acids can be strong or weak depending on how much they ionise in solution.

2. Examples of Common Acids

2.1 Strong Acids (Ionise completely in water → High H_3O+$$H_3O^+ concentration)

✔ Hydrochloric acid $(HCl)$ → Found in stomach acid and used in cleaning agents.

✔ Sulphuric acid $(4H_2SO_4)$ → Used in car batteries and fertiliser production.

✔ Nitric acid $(HNO₃)$ → Used in fertilisers and explosives.

2.2 Weak Acids (Ionise partially in water → Lower $H_3O+H_3O^+$ concentration)

✔ Ethanoic acid $(CH₃COOH) →$ Found in vinegar.

✔ Citric acid → Present in citrus fruits like lemons and oranges.

✔ Carbonic acid $(H_2CO_3) →$ Found in soft drinks and carbonated water.

3. Properties of Acids

✔ Conduct electricity in solution (due to ionisation).

✔ React with metals to form hydrogen gas.

✔ React with carbonates to produce carbon dioxide gas.

✔ Turn blue litmus paper red.

✔ Have a $pH$ below 7.