Based on the value of temperature increase, the best solute to be used in the hot pack is calcium chloride.
Exothermic reactions are reactions in which heat is liberated or given by the substances reacting.
The reaction in hot packs are exothermic reactions.
Based on the increase in temperature observed when 20 g of each solute is  mixed into separate containers that each held 50 mL of 24°C water, the best solute to be used in the hot pack is calcium chloride.
In conclusion, exothermic reactions give off heat.
Learn more about exothermic reactions at: https://brainly.com/question/2924714
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