To melt 800 g of ice at 0°C, you would need to supply 267,200 joules of heat energy of 267,200 J
The heat of fusion is the amount of heat energy required to change 1 gram of a solid substance into a liquid at its melting point under constant pressure.
The heat of fusion of water is 334 J/g or 80 cal/g. This means that it takes 334 joules of heat energy to change 1 gram of ice at 0°C into 1 gram of water at 0°C.
The heat of fusion of a substance can be calculated using the following equation:
Q = m * L_f
where:
Q is the amount of heat energy required to melt the substance (J or cal)
m is the mass of the substance (g)
L_f is the latent heat of fusion of the substance (J/g or cal/g)
Q = 800 g * 334 J/g
Q= 267,200 J