Describe a neutralization reaction and give an example with a salt formed.

• A. A base reacts with water to form an acid.
• B. An acid reacts with a base to form a salt and water; example: HCl + NaOH -> NaCl + H2O.
• C. A salt forms without water.
• D. A metal reacts with acid to produce hydrogen gas.

Answer: (B)

Neutralization is the reaction between an acid and a base that forms a salt and water. In this type of reaction, the hydrogen ion (H+) from the acid combines with the hydroxide ion (OH−) from the base to make water, while the remaining ions pair up to form a salt. For example, when hydrochloric acid (an acid) reacts with sodium hydroxide (a base), the H+ from the acid and the OH− from the base create H2O, and the sodium (Na+) and chloride (Cl−) ions come together to form sodium chloride (NaCl), a salt. This process often releases heat and moves the solution toward neutral pH. The other scenarios don’t fit: a base reacting with water to form an acid isn’t a neutralization, a salt forming without water isn’t the defining product of a neutralization reaction, and a metal reacting with acid to produce hydrogen gas isn’t forming a salt and water.