Question

Determine if each of the process is exothermic or endothermic?

a) Isopropyl alcohol evaporating from the skin

b) The reaction that occurs in a chemical cold pack used to ice athletic injuries

c) Water condensing from steam

d) Natural gas burning on stove

Answer 1

First, let us define exothermic process

exothermic --> the system/reaction releases heat, therefore, will increase the energy/temperature of the surroundings.

exndothermic -->  the system/reaction absorbs heat, therefore, will decrease the energy/temperature of the surroundings.

a)

isopropyl alcohol is ABSORBING heat form your skin, therefore this must be ENDOthermic

b)

the Cold pack is ABSORBING heat from the injury, therefore, this is also ENDOthermic

c)

Water is a lower state energy, therefore, steam is losing energy, i.e. EXOTHERMIC process

d)

natural gas burns, clearly, releases energ, so it is EXOTHERMIC