Question

Suppose that a combustion reaction that powers a camping stove releases 300kJ of heat, thereby causing water in a pot to absorb 200 kJ of heat. What is the efficiency of heat transfer to the water? (I can see by intuition that the efficiency must be 2/3 or 67%, but I do not know the proper way to solve these problems!) Thanks.

Answer 1

You are almost there.

The amount of heat released = 300 KJ

The amount of heat transferred to the water = 200 KJ

The amount of heat lost = 100 Kj

The efficiency of heat transfer can be calculated by using the formula

efficiency of heat transfer = amount of heat transferred x 100 % /  amount of heat released

We know the values. Just substitute and get the efficiency

The efficiency of heat transfer = 200 x 100 % / 300 = 66.67 %