Question

How much heat is necessary to change 500g of ice at 263K to water at 293K

Answer 1

$m=500 \;g \\ T_1= 263-273 = -10 \;°C \\ T_2 = 293 - 273 = 20 \; °C$

Specific heat capacity for Ice = 2.1 J/g°C

Latent heat of fusion of Ice = 335 J/g

Specific heat capacity for Water = 4.2 J/g°C

$Q_1 = 10\times 500 \times 2.1 = 10500 \;J$ (from -10 °C to 0 °C)

$Q_2 = 20 \times 500 \times 4.2 = 42000 \;J$ (from 0 °C to 20 °C)

$Q_3 = 500 \times 335 = 167500 \;J$ (heat of melting)

Total heat $Q_T = 10500+42000+167500 = 220000\;J$

Answer: 220 kJ