Question

How much heat would be needed to completely evaporate 31.5 g of boiling water at a temperature of 100 "C? Express your answer in units of joules.

Answer 1

Answer:

Heat needed = 71.19 J

Explanation:

Here heat required can be calculated by the formula

            H = mL

M is the mass of water and L is the latent heat of vaporization.

Mass of water, m = 31.5 g = 0.0315 kg

Latent heat of vaporization of water = 2260 kJ/kg

Substituting

            H = mL = 0.0315 x 2260 = 71.19 kJ

Heat needed = 71.19 J