Question

Statements given below are incorrect. Write the correct statements :

A lot of heat is needed to start the reaction between sodium hydroxide and hydrochloric acid.

Answer 1

• Hydrochloric acid reacts with Sodium hydroxide solution to form Sodium chloride (salt) and water with the evolution of a lot of heat.
• $\underset{\mathrm{Sodium}\mathrm{hydroxide}}{\mathrm{NaOH}\left(\mathrm{aq}\right)}+\underset{\mathrm{Hydrochloric}\mathrm{acid}}{\mathrm{HCl}\left(\mathrm{aq}\right)}\to \underset{\mathrm{Sodium}\mathrm{chloride}}{\mathrm{NaCl}\left(\mathrm{aq}\right)}+\underset{\mathrm{Water}}{{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)}+\mathrm{Heat}$
• This is a type of exothermic reaction and is also known as a neutralization reaction because in the above reaction acid reacts with a base to form salt and water.
• In an exothermic reaction, heat is evolved in the reaction.

Hence, the correct statement is ‘No heat is needed to start the reaction between Sodium hydroxide and Hydrochloric acid but heat is evolved when Sodium hydroxide reacts with Hydrochloric acid’.​