The reaction between an acid and a base is known as _____.

Neutralization

The correct answer is option 3. Neutralization.

Neutralization is a chemical reaction that occurs between an acid and a base to produce a salt and water. It involves the transfer of protons \((H^+\, \ ions)\) from the acid to the base, resulting in the formation of water and salt.

Here's the general equation for neutralization:

\(Acid\, \ +\, \ Base \longrightarrow Salt\, \ +\, \ Water\)

During neutralization, the acidic hydrogen ions \((H^+)\) from the acid combine with the hydroxide ions \((OH^-)\) from the base to form water molecules \((H_2O)\). The remaining ions from the acid and base combine to form a salt. The salt formed depends on the specific acid and base involved in the reaction.

For example, in the neutralization reaction between hydrochloric acid \((HCl)\) and sodium hydroxide \((NaOH)\), the equation would be:

\(HCl + NaOH \longrightarrow NaCl + H_2O\)

In this reaction, hydrogen ions from hydrochloric acid combine with hydroxide ions from sodium hydroxide to form water \((H_2O)\), while sodium ions from the base combine with chloride ions from the acid to form sodium chloride \((NaCl)\), which is commonly known as table salt.

Neutralization reactions are important in various fields such as chemistry, environmental science, and everyday life. They are utilized in processes like water treatment, pH regulation, and the preparation of various chemical compounds.