(Solved): 11. Calculate the standard enthalpy change and the standard entropy change for the combustion of 1 ...

11. Calculate the standard enthalpy change and the standard entropy change for the combustion of 1 mole of acetylene \( \left(\mathrm{C}_{2} \mathrm{H}_{2}\right) \) at \( 25^{\circ} \mathrm{C} \) under 1 atm. pressure. \[ \mathrm{C}_{2} \mathrm{H}_{2}(\mathrm{~g})+2.5 \mathrm{O}_{2}(\mathrm{~g}) \rightarrow 2 \mathrm{CO}_{2}(\mathrm{~g})+\mathrm{H}_{2} \mathrm{O}_{(1)} \] \[ \begin{array}{l} \mathrm{S}^{\oplus}\left[\mathrm{C}_{2} \mathrm{H}_{2}(\mathrm{~g})\right] \quad=200.94 \mathrm{~J} /(\mathrm{K} . \mathrm{mol}) \quad \mathrm{S}^{\oplus}\left[\mathrm{CO}_{2(\mathrm{~g})}\right] \quad=213.74 \mathrm{~J} /(\mathrm{K} . \mathrm{mol}) \\ \mathrm{S}^{\ominus}\left[\mathrm{O}_{2}(\mathrm{~g})\right] \quad=205.14 \mathrm{~J} /(\mathrm{K} . \mathrm{mol}) \quad \mathrm{S}^{\ominus}\left[\mathrm{H}_{2} \mathrm{O}(\mathrm{l})\right] \quad=69.91 \mathrm{~J} /(\mathrm{K} . \mathrm{mol}) \\ \Delta \mathrm{H}^{\Theta}\left[\mathrm{CO}_{2(\mathrm{~g})}\right]=-393.5 \mathrm{~kJ} / \mathrm{mol} ; \quad \Delta \mathrm{H}^{\ominus}\left[\mathrm{H}_{2} \mathrm{O}(\mathrm{l})\right]=-286 \mathrm{~kJ} / \mathrm{mol} ; \Delta \mathrm{H}^{\Theta}\left[\mathrm{C}_{2} \mathrm{H}_{2}(\mathrm{~g})\right]=227 \mathrm{~kJ} / \mathrm{mol} \\ \end{array} \]