Question

How much heat does it take to melt 5.0g solid copper?

Answer 1

Answer:

$Q=1.04kJ$

Explanation:

Hello,

In this case, for latent heat (phase change) we need to consider the enthalpy associated with the involved process, here, melting or fusion; thus, the enthalpy of fusion of copper is 13.2 kJ/mol, therefore, the heat is computed as:

$Q=m\Delta H_{fus}$

Nevertheless, since the given enthalpy is per mole of copper, we need to use its atomic mass to perform the correct calculation as follows:

$Q=5.0g*\frac{1mol}{63.54}* 13.2\frac{kJ}{mol}\\ \\Q=1.04kJ$

Which is positive as it needs to be supplied to the system.

Best regards.