How can I calculate the standard reaction enthalpy if I lack one formation enthalpy?

Question

I have this reaction, for which I need the standard enthalpy of reaction:

$$\ce{CuO (s) + H2S (g) \rightarrow CuS (s) + H2O (g)}$$

This is the data from the NIST web book (standard formation enthalpies, $\mathrm{kJ}\cdot\mathrm{mol}^{-1}$):

• $\ce{CuO (s)}$: -156.60
• $\ce{H2S (g)}$: -20.5
• $\ce{H2O (g)}$ -241.83

There are no data tabulated for $\ce{CuS (s)}$, so how can I compute the standard reaction enthalpy lacking this data?

Answer 1

The standard enthalpy of formation of $\ce{CuS}\,\mathrm{(s)}$ is -48.4 $\mathrm{kJ}\cdot\mathrm{mol}^{-1}$. See this reference for your requested data and more.