Suppose you want to heat a 600 mL cup of water in the microwave from 20° to 100°C. Water has a specific heat capacity of 4.184 J/g°C and a density of 1.00 g/mL in this temperature range. How much energy is required to heat the cup of water?

The quantity of heat required to to heat the cup of water through a temperature change of 80°C = 200.83 kJ

Explanation:

Density = mass/Volume.

∴ mass = Density * volume

Where Density of water = 1.00 g/mL, volume of water = 600 mL

Mass = 1 * 600 = 600 g.

(Q) = cm (ΔT) ... equation 1

Where Q = quantity of heat, c = specific heat capacity of water, m = mass of water, ΔT = T₁-T₂ = change in temperature.

Where c = 4.184 J/g°C, m = 600 g, ΔT = T₁-T₂ = 100 - 20 = 80°C

Substituting these values into equation 1,

Q = 4.184 * 600 * 80

Q = 200832 J = 200.83 kJ

Therefore the quantity of heat required to to heat the cup of water through a temperature change of 80°C = 200.83 kJ