Question

Quicklime $\left(\text{CaO}\right)$ reacts with water to form slaked lime ${\text{Ca(OH)}}_2$. During this process:

• A. Heat is absorbed
• B. Heat is released
• C. Heat is absorbed and then released
• D. Heat is neither absorbed nor released

Answer 1

The correct option is B Heat is released

Quicklime (calcium oxide, $\text{CaO}$) on combining with water, gets converted to slaked lime (calcium hydroxide, ${\text{Ca(OH)}}_2$) with the liberation of the enormous amount of heat. Hence, the reaction is exothermic in nature.

The reaction involved is:
$\text{CaO (s)}+{\text{H}}_2\text{O (l)}⟶{\text{Ca(OH)}}_2\text{(s)}+\text{Heat}$