Answer:
20.67 kcal of energy is released.
Explanation:
It is given that, an exothermic reaction releases 86.5 kJ. We need to convet kJ to calories.
Since,
1 kcal = 4.184 kJ
So,
1 kJ = 0.239 kcal
For 86.5 kJ,
86.5 kJ = (0.239 × 86.5) kcal
86.5 kJ = 20.67 kcal
So, 20.67 kcal of energy is released.