Which statement correctly describes the difference between endothermic and exothermic reactions?

• A. Both endothermic and exothermic reactions absorb heat from the surroundings.
• B. Endothermic reactions absorb heat from the surroundings, while exothermic reactions release heat to the surroundings.
• C. Endothermic reactions release heat to the surroundings, while exothermic reactions absorb heat from the surroundings.
• D. Both endothermic and exothermic reactions release heat to the surroundings.

Answer: (B)

Verified step by step guidance

1. Step 1: Understand the definitions of endothermic and exothermic reactions. Endothermic reactions are those that absorb heat from their surroundings, causing the surroundings to get cooler.
2. Step 2: Recognize that exothermic reactions release heat to their surroundings, which causes the surroundings to get warmer.
3. Step 3: Compare the heat flow in both types of reactions: in endothermic reactions, heat flows into the system, while in exothermic reactions, heat flows out of the system.
4. Step 4: Use the concept of enthalpy change (\$\Delta H\$) to describe these processes: for endothermic reactions, \$\Delta H > 0\$ (positive), indicating heat absorption; for exothermic reactions, \$\Delta H < 0\$ (negative), indicating heat release.
5. Step 5: Conclude that the correct statement is: 'Endothermic reactions absorb heat from the surroundings, while exothermic reactions release heat to the surroundings.'