Sodium hydroxide
Reaction with acids

Sodium hydroxide reacts with protic acids to produce water and the corresponding salts. For example, when sodium hydroxide reacts with hydrochloric acid, sodium chloride is formed:

In general, such neutralization reactions are represented by one simple net ionic equation:

This type of reaction with a strong acid releases heat, and hence is exothermic. Such acid–base reactions can also be used for titrations. However, sodium hydroxide is not used as a primary standard because it is hygroscopic and absorbs carbon dioxide from air.
detectable_content:postscript