Concept:A process that absorbs heat from its surroundings causes the surroundings to become cold.
Such a process is called endothermic.
Explanation:When
NH4Cl(s) is dissolved in water, the container feels cold to touch.
This means heat energy is absorbed from the water and the container during dissolution.
As a result, the temperature of the surroundings decreases.
Therefore, the dissolution of
NH4Cl(s) in water is an endothermic process.
An exothermic process would release heat and make the container warm.
The cold feeling does not directly indicate saturation or high solubility.
Answer:A. The process is endothermic