How do acids react with bases to form salts?

Acids react with bases in a neutralisation reaction to form salts and water.

In a neutralisation reaction, an acid and a base combine to form a salt and water. This process is a fundamental concept in chemistry, particularly in the study of acid-base reactions. The term 'neutralisation' is used because the acid's properties are neutralised by the base, and vice versa, resulting in a pH of 7, which is considered neutral.

The general equation for a neutralisation reaction is: Acid + Base → Salt + Water. For example, when hydrochloric acid (HCl) reacts with sodium hydroxide (NaOH), the products are sodium chloride (NaCl) and water (H2O). This can be represented as: HCl + NaOH → NaCl + H2O.

The type of salt that forms depends on the specific acid and base involved in the reaction. For instance, if sulphuric acid (a strong acid) reacts with potassium hydroxide (a strong base), the resulting salt is potassium sulphate.

In these reactions, the hydrogen ions (H+) from the acid react with the hydroxide ions (OH-) from the base to form water (H2O). The remaining ions then combine to form the salt. This is why the reaction is also sometimes referred to as a 'double replacement reaction', as both the acid and the base 'swap' a part of their molecules to form new compounds.

Understanding these reactions is crucial for many applications in chemistry and related fields. For example, neutralisation reactions are used in agriculture to treat acidic soil, in medicine to develop antacids, and in environmental science to neutralise acidic pollutants.