Question

How much energy is required to heat 2kg of ice from -5°c to 0°c

Answer 1

Explanation:

total heat = Heat required to convert 2 kg of ice to 2 kg of water at 0 °C + Heat required to convert 2 kg of water at 0 °C to 2 kg of water at 20 °C.

Heat=mhfg+mCpΔT

Here, m ( mass of ice) = 2 kg

hfg (latent heat of fusion of ice) = 334 KJ

Cp of water (specific heat) = 4.187 KJ/Kg-K

ΔT(Temperature difference) = 20 °C

Therefore, Heat required = 2 x 334 + 2 x 4.187 x (20 - 0 )

Heat reqd= 835.48 KJ

Therefore, to melt 2 kg of ice 835.48 KJ of heat is required.