Endothermic reactions can be used in emergency sports injury treatment packs. What is true about these packs?Question 7AnswerA.Absorb energy from the surroundings and transfer it to the injury.B.Can be re-used.C.Usually contain ammonium nitrate and water in separate compartments.D.Cause the temperature of the surroundings to increase.

The correct answer is A and C.

A. Endothermic reactions absorb energy from the surroundings. In the case of a sports injury pack, this energy is absorbed from the body, causing a cooling effect on the injury.

C. These packs usually contain ammonium nitrate and water in separate compartments. When the pack is activated (usually by squeezing or breaking an internal barrier), the ammonium nitrate dissolves in the water. This process is endothermic - it absorbs heat from the surroundings, causing the pack to feel cold.

B. These packs cannot be reused. Once the chemical reaction has occurred, it cannot be reversed, so the pack will not get cold again after it has returned to room temperature.

D. These packs do not cause the temperature of the surroundings to increase. In fact, they do the opposite - they absorb heat from the surroundings, causing the pack (and the injury it is applied to) to cool down.