How much energy is required to melt 25g of ammonia at the melting point? Heat of vaporization is 327 cal/g and Heat of fusion is 84 cal/g.

Question

How much energy is required to melt 25g of ammonia at the melting point?

Heat of vaporization is 327 cal/g and Heat of fusion is 84 cal/g.

Answer 1

To melt something at its melting point, we multiply the mass of the substance by the ∆Hfusion.

25 g x 84 cal/g = 2100 cal

If you want this in joules, use the conversion factor that 1 cal = 4.184 joules

2100 cal x 4.184 J/cal = 8786 J