What is the heat of reaction for C6H6 + 3H2 -> C6H12, if heat of formation of C6H6, H2, and C6H12 are 25 J, 5 J and 50 J respectively?

Question

What is the heat of reaction for C6H6 + 3H2 -> C6H12, if heat of formation of C6H6, H2, and C6H12 are 25 J, 5 J and 50 J respectively?

(a) 10 J

(b) 20 J

(c) 30 J

(d) 35 J

Answer 1

Right answer is (a) 10 J

The explanation is: Heat of reaction = 50 – 3*5 – 25 = 10 J.