Which statement describes an endothermic process?

Which statement describes an endothermic process?

• A. It releases heat to the surroundings
• B. It absorbs heat from the surroundings
• C. It results in a negative enthalpy change
• D. It always occurs at constant volume

Answer: (B)

Endothermic processes involve heat flowing into the system from the surroundings. Because heat is entering, the system gains energy, so the heat q is positive for the system and the enthalpy change ΔH is positive at constant pressure. That positive heat absorption is exactly what choosing the option that describes absorbing heat from the surroundings conveys. In contrast, releasing heat to the surroundings describes an exothermic process with a negative ΔH, and constant volume is not a defining requirement—endothermic behavior can occur at various volumes depending on the context.

Endothermic processes involve heat flowing into the system from the surroundings. Because heat is entering, the system gains energy, so the heat q is positive for the system and the enthalpy change ΔH is positive at constant pressure. That positive heat absorption is exactly what choosing the option that describes absorbing heat from the surroundings conveys. In contrast, releasing heat to the surroundings describes an exothermic process with a negative ΔH, and constant volume is not a defining requirement—endothermic behavior can occur at various volumes depending on the context.