The strength of an acid or base is determined by how completely they dissociate in water. The more completely an acid or base dissociates, the stronger it is. The strength of an acid or base is also affected by the concentration of the solution. The more concentrated the solution, the stronger the acid or base.

The pH of a solution is a measure of the concentration of hydrogen ions (H+) in the solution. The lower the pH, the higher the concentration of hydrogen ions and the stronger the acid. The higher the pH, the lower the concentration of hydrogen ions and the stronger the base.

The pH scale ranges from 0 to 14. A pH of 7 is neutral. A pH below 7 is acidic. A pH above 7 is basic.

The following table shows the pH values of some common acids and bases:

| Acid | pH |

|---|---|

| Hydrochloric acid | 1 |

| Sulfuric acid | 1 |

| Nitric acid | 1 |

| Acetic acid | 2.4 |

| Carbonic acid | 3.8 |

| Base | pH |

|---|---|

| Sodium hydroxide | 13 |

| Potassium hydroxide | 13 |

| Calcium hydroxide | 12.4 |

| Magnesium hydroxide | 10.5 |

| Ammonia | 11.6 |