Question

A backpacker wants to carry enough fuel to heat 2.2 kg of water from 28 ∘C to 100.0 ∘C.

If the fuel he carries produces 36 kJ of heat per gram when it burns, how much fuel should he carry? (For the sake of simplicity, assume that the transfer of heat is 100 % efficient.)

Answer 1

18.48g

Step-by-step explanation:

The heat energy absorbed by the water for the temperature to change from 28°C to 100°C.

Using the formula for calculating energy MC∅, where ∅ is the temperature change, we get:

2.2kg× 4.2kJ/kgK×(100-28)K=665.28kJ

Therefore the fuel carried carried should produce 665.28kJ of energy.

Thus he should carry: 665.28kJ/36kJ/g= 18.48g fuel assuming that the fuel burns completely.