Neutralization reaction is a kind of double decomposition reaction in chemical reaction, which refers to the reaction of acid and alkali exchange components to form salt and water. In the process of neutralization, hydrogen ions in acid and hydroxyl ions in alkali will combine to form water. The process of neutralization reaction will release heat, which belongs to exothermic reaction. Molar hydroxide reacts with hydrogen ions to absorb 55.90 kilojoules of heat.

Reaction principle:

After being dissolved in water, acids and bases are ionized into anions and cations that move freely in water. For example, HCl (hydrochloric acid) is ionized into hydrogen ions (H+) and chloride ions (Cl-), and NaOH (caustic soda) is ionized into sodium ions (Na+) and hydroxide ions (OH-). Hydrogen ions and hydroxide ions combine to form water that is extremely difficult to ionize, so what is left in the solution is sodium ions and chloride ions.

Sodium ions and chloride ions are still ionized in the solution and will not combine. But the product is NaCl (salt). So the essence of neutralization reaction is that acid and alkali react to produce salt and water.