Question

Calculate the total amount of heat required to convert 100g ice at 0°C to steam at 100°C. 
(Specific latent heat of fusion of ice = 336 J/g, specific latent heat of vaporization of steam = 2260 J/g, specific heat capacity of water = 4.2 J/g°C).

Answer 1

Heat required to convert 100 g ice at 0°C to water at 0°C

= Mass × Specific latent heat of fusion of ice

= 100 × 336 = 3600 J

Heat required to raise the temperature of 100 g water from 0°C to 100°C

= Mass × Specific heat capacity of water × Rise in temperature

= 100 × 4.2 × (100 - 0) = 42000 J

Heat required to convert 100 g water at 100 °C to steam at 100°C

= Mass × Specific latent heat of vaporization of steam

= 100 × 2260 = 226000 J

Total heat required = 33600 + 42000 + 226000 = 301600 J.