Which of the following compounds is used in instant cold pack to injuries of athletes?

Options

A. `CaCl_(2)`
B. `NH_(4)NO_(3)`
C. `MgSO_(4)`
D. Both (1) and (3)

Answer

2

Explanation

Dissolution of `CaCl_(2)` or `MgSO_(4)` in water is exo-thermic, causing the temperature of the water to rise from its initial value of `25^(@)C`.
Dissolution of `NH_(4)NO_(3)` is endothermic, causing the temperature of the water to fall from its initial value of `25^(@)C`.