Question 26
Energy ChangesThe ΔH for the reaction represented by the energy profile above is
- A.-100 kJ mol-1
- B.+100 kJ mol-1
- C.+50 kJ mol-1
- D.-50 kJ mol-1
Show the answer and explanation
Answer: D (-50 kJ mol-1)
Explanation
ΔH = energy of products − energy of reactants. The curve starts at 100 kJ and ends at 50 kJ, so ΔH = 50 − 100 = −50 kJ mol-1 (exothermic).