If a reaction is exothermic, which of the following statements is correct?

• A. The reaction absorbs heat from its surroundings.
• B. The reaction releases heat to its surroundings.
• C. The temperature of the surroundings decreases.
• D. The enthalpy change, ΔH, is positive.

Answer: (B)

Verified step by step guidance

1. Understand the definition of an exothermic reaction: it is a chemical reaction that releases heat to its surroundings.
2. Recall that when a reaction releases heat, the enthalpy change (ΔH) is negative because the system loses energy.
3. Recognize that since heat is released to the surroundings, the temperature of the surroundings typically increases, not decreases.
4. Identify that the statement 'The reaction absorbs heat from its surroundings' is incorrect for an exothermic reaction; this describes an endothermic process.
5. Conclude that the correct statement is 'The reaction releases heat to its surroundings' and that ΔH is negative, not positive.