Calculate the quantity of heat required to raise the temperature of 5 kg of water from 0°C to 100°C. Assume the specific heat capacity of water is 4200 J/ (kg °C). Quantity of heat energy, Q = mc ( t 2 – t 1) = 5 kg × 4200 J/ (kg °C) × (100 – 0)°C. = 5 × 4200 × 100. = 2100000 J or 2100 kJ or 2.1 MJ. Problem 4.