How much heat energy is necessary to raise the temperature of 5 kg of water
from 20oC to 100oC ?
Suppose, m= 5 kg and c= 1 kcal/ kg oC
Then, change in temperature Δ t = 100-20=80oC
Energy to be supplied to water = energy gained by water = mass of water × specific heat of water × change in temperature of water
= m × c × Δ t
= 5 × 1 × 80 = 5 × 80
=400 kcal