What do you call a reaction that absorbs heat from the surroundings?

• A. A spontaneous reaction
• B. An endothermic reaction
• C. An exothermic reaction
• D. A double displacement reaction

Answer: (C)

A reaction that absorbs heat from the surroundings is endothermic. In an endothermic process, energy is taken in by the reacting substances, so the enthalpy change is positive and the surroundings may feel cooler as heat flows into the system. A familiar example is dissolving ammonium nitrate in water, which makes the solution feel cold.

The opposite term, exothermic, describes reactions that release heat to the surroundings, warming them. The other two options aren’t about heat flow: spontaneous refers to whether a reaction can occur without extra energy under given conditions (not specifically about heat transfer), and a double displacement reaction describes how ions swap partners in a reaction, not the heat change.