Question

7. How much thermal energy is absorbed when 10.0 g of ice at 0.0 degrees C changes phase to liquid water at 0.0 degrees C? The molar mass, M, of water is 18.02 g/mol and the theoretical heat of fusion, Hfus, of water is 6.01 kJ/mol

Answer 1

Answer:

3.34 kJ

Explanation:

FIrst of all, we need to calculate the number of moles corresponding to 10.0g of ice. This is given by

$n=\frac{m }{M_m}$

where

$M_m = 18.02 g/mol$ is the molar mas

m = 10.0 g is the mass

Substituting

$n=\frac{m}{M_m}=\frac{10 g}{18.02 g/mol}=0.555 mol$

Now we know that the heat of fusion is

$H_{fus}=6.01 kJ/mol$

so the thermal energy needed to fuse the ice is

$Q=n H_{fus} = (0.555 mol)(6.01 kJ/mol)=3.34 kJ$