The molar mass is calculated by dividing the given mass of copper by the moles of copper determined from the reaction stoichiometry.

Here is the continuation of the solution for question 5(a)(ii):

Step 4: Calculate the molar mass of the copper metal.
The molar mass is calculated by dividing the given mass of copper by the moles of copper determined from the reaction stoichiometry.

$$\text{Molar mass of Cu} = \frac{\text{Mass of Cu}}{\text{Moles of Cu}}$$ $$\text{Molar mass of Cu} = \frac{0.04 \text{ g}}{0.00625 \text{ mol}}$$ $$\text{Molar mass of Cu} = 6.4 \text{ g/mol}$$

The molar mass of the copper metal, based on the given data, is $\boxed{\text{6.4 g/mol}}$.