Which statement is true about exothermic processes?

Which statement is true about exothermic processes?

• A. They require energy input
• B. They release heat to surroundings
• C. They always increase temperature of surroundings
• D. They have zero enthalpy change

Answer: (B)

Exothermic processes move energy out of the system as heat into the surroundings. That transfer of heat corresponds to a negative enthalpy change, meaning the system releases energy. Because of that heat release, the statement that exothermic processes release heat to the surroundings is the true description. The other ideas conflict with this behavior: needing energy input describes endothermic processes, zero enthalpy change would imply no heat transfer, and saying the surroundings always heat up is too absolute since the observed temperature change depends on the relative heat capacities and masses involved.

Exothermic processes move energy out of the system as heat into the surroundings. That transfer of heat corresponds to a negative enthalpy change, meaning the system releases energy. Because of that heat release, the statement that exothermic processes release heat to the surroundings is the true description. The other ideas conflict with this behavior: needing energy input describes endothermic processes, zero enthalpy change would imply no heat transfer, and saying the surroundings always heat up is too absolute since the observed temperature change depends on the relative heat capacities and masses involved.