Question

How much heat energy is required to melt 337.1 g of HBr? The molar heat of fusion of HBr is 2.41 kJ/mol.

Answer 1

we are given the molar heat of fusion of HBr of 2.41 kJ/mol. The amount of HBr given is 337.1 grams. The molar mass of HBr is equal to 80.91 g/mol which means the number of moles is equal to 4.17 moles. Thus the total amount of heat energy is equal to 10.04 kJ.

Answer 2

$m=337,1g\\ M_{HBr}=81\frac{g}{mol} \ \ \Rightarrow \ \ n=\frac{m}{M}=\frac{337,1g}{81\frac{g}{mol}}=4,2mol$

If  2,41kJ   --- require ----- 1mol
                          so
       Q       ---- require ----- 4,2mol

$Q=\frac{4,2mol*2,41kJ}{1mol}=10,122kJ$