Question

The reaction in which heat energy is evolved:

• A. Endothermic reactions
• B. Exothermic reaction
• C. Enthalpy change reactions
• D. None of the above

Answer 1

The correct option is B

Exothermic reaction

Explanation of the correct answer:

The correct answer is Option B.

Exothermic reactions are the ones in which heat is released or evolved when a reaction takes place.

Example: All neutralization reactions are exothermic reactions.

$\mathrm{NaOH}\left(\mathrm{aq}\right)+\mathrm{HCl}\left(\mathrm{aq}\right)\to \mathrm{NaCl}\left(\mathrm{s}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)+∆$

The explanation for incorrect options:

Endothermic reactions are the ones in which heat is required for the reaction to take place.

Example: The melting of ice to form water.

Enthalpy change reaction includes both the endothermic and exothermic types of reaction. Enthalpy means energy.

Hence, an exothermic reaction is a correct option.