How many calories of heat?

Specific latent heat of fusion of water, Lf = 79.72 cal/g
Specific heat capacity of water, c = 1 cal/(g°C)
Specific latent heat of vaporization, Lv = 541.3 cal/g

Heat required to melt 15.0 g of ice at 0°C to water at 0°C
= m Lf
= 15.0 × 79.72 cal

Heat required to change 15.0 g of water at 0°C to 100°C
= m c ΔT
= 15.0 × 1 × 100 cal

Heat required to evaporate 15.0 g of water at 100°C to steam at 100°C
= m Lv
= 15.0 × 541.3 cal

Total heat required to change 15.0 g of ice at 0°C to steam at 100°C
= (15.0 × 79.72 + 15.0 × 1 × 100 + 15.0 × 541.3) cal
= 10800 cal (to 3 sig. fig.)

use H=mc * change in temp