Question

a) How much energy would be required to melt 500 grams of ice at 0°C to water at 0°C?

Answer 1

Heat required = Q = 40 kcal

Further explanation

Given

mass of 500 g ice

Required

Heat required

Solution

The heat to change the phase can be formulated :  

• Q = m.Lf (melting/freezing)  
• Q = m.Lv (vaporization/condensation)  

Lf=latent heat of fusion  

Lv=latent heat of vaporization  

Lf for water = 334 kj/kg=6.01 kJ/mol = 80 cal/g

Phase change(ice to water)

Q=  500 g x 80 cal/g

Q = 40 kcal