The heat of fusion of water is 80 cal/

g. How much energy is needed to melt 0.05 kg of ice?

80 cal / g is same as 80 calories in each 1 gram. so,

80 cal = 1 gram

first, we need to convert the kg into grams. all you have to do is multiply by 1000 or move the decimal three times to the right.

0.05 kg = 50.0 grams

50.0 g (80 cal / 1 gram) = 4000 calories