Consider the following reactions at 298 K: (1) (2) A direct experimental measurement…

CHEMISTRY · Subjective · AP · Chemistry · Thermodynamics and Electrochemistry · Thermodynamics and Electrochemistry

Problem

Consider the following reactions at 298 K: (1)

\text{C(graphite)}+\dfrac{1}{2}\,\text{O}_{2}(g) \rightarrow \text{CO}(g)

\Delta S^{\circ}_{1}= +39\;\text{J mol}^{-1}\text{K}^{-1}

(2)

\text{CO}(g)+\dfrac{1}{2}\,\text{O}_{2}(g) \rightarrow \text{CO}_{2}(g)

\Delta S^{\circ}_{2}= -174\;\text{J mol}^{-1}\text{K}^{-1}

A direct experimental measurement gives

\Delta S^{\circ}_{\text{exp}}= +214\;\text{J mol}^{-1}\text{K}^{-1}

for the reaction

\text{C(graphite)}+\text{O}_{2}(g) \rightarrow \text{CO}_{2}(g)

Calculate the theoretical

\Delta S^{\circ}

predicted from reactions (1) and (2). Then state whether the experimental value is consistent with the prediction if agreement requires

|\Delta S^{\circ}_{\text{pred}}-\Delta S^{\circ}_{\text{exp}}|\le 5\;\text{J mol}^{-1}\text{K}^{-1}