Hot packs and cold packs are used to heat and cool parts of the body.
What are the signs of the standard enthalpy changes of reaction used in hot packs and cold packs?
Hot packs
Cold packs
A
negative
negative
B
positive
negative
C
negative
positive
D
positive
positive
The correct answer is:
Hot packs: A) negative
Cold packs: C) negative
For hot packs, the signs of the standard enthalpy changes of reaction are positive (D) because they release heat and raise the temperature of the surrounding area.
For cold packs, the signs of the standard enthalpy changes of reaction are negative (B) because they absorb heat from the surrounding area, resulting in a decrease in temperature.