Question

The heat of fusion for an unknown substance is 485J/g. How much heat is required to melt a 92-g sample of this substance at its melting point?

Answer 1

Step 1

Melting is the change from a solid phase to a liquid phase. This process requires heat (absorbs heat).

Mathematically,

$Q\text{ = m x }\lambda$

Q = heat required to melt the substance

m = mass = 92 g

Lamda = the heat fusion = 485 J/g

So,

$Q\text{ = 92 g x 485 J/g = 44620 J}$

Answer: Q = 44,620 J