2. For water: $\Delta H_{\text{vap}} = 40.7 \ \text{kJ mol}^{-1}$
Now simply multiply it by the amount of water you have in terms of moles: $q = \Delta H_{\text{vap}} \cdot 10 \ \text{g} \cdot \frac{1 \ \text{mol}}{18.02 \ \text{g}}$