Question

Describe how a hot pack works, how does a cold pack work? Are these reactions exothermic or endothermic? Include a description of the chemicals used in your answer. Post your answer on the appropriate discussion topic.

Type the answer will be better for me, thanks!

Cold pack- ice pack

Answer 1

Either hot pack or cold pack, the working principle is the dissolution of salt in water. During the dissolution, either heat is liberated ( exothermic reaction) or heat is absorbed ( endothermic reaction). if heat is liberated in hot packs and heat is abosrbed in cold packs

for example when urea is dissolved in water, heat is abosrbed this is cold pack

when calcium chloride is dissolved in water, heat is absorbed and this is hot pack

The dissolution is expressed as heat of dissolution and this heat of dissolution is measured using coffe cup calorimeter,