Consider the following compounds and their standard free energies of formation: $\begin{array}{|c|c|c|c|c|}
\hline 1&2&3&4&5\
\hline \begin{array}{c}
\mathrm{C}_{6} \mathrm{H}_{12}(\mathrm{l}) \
\text { cyclohexane }
\end{array} & \begin{array}{c}
\mathrm{CH}_{3} \mathrm{OH}(\mathrm{l}) \
\text { methanol }
\end{array} & \begin{array}{c}
\mathrm{N}_{2} \mathrm{H}_{4}(\mathrm{l}) \
\text { hydrazine }
\end{array} & \begin{array}{c}
\mathrm{H}_{2} \mathrm{O}_{2}(\mathrm{l}) \
\text { hydrogen peroxide }
\end{array} & \begin{array}{c}
\mathrm{CS}_{2}(\mathrm{l}) \
\text { carbon disulfide }
\end{array} \
\hline+6.4 \mathrm{~kJ} \cdot \mathrm{mol}^{-1} & -166 \mathrm{~kJ} \cdot \mathrm{mol}^{-1} & +149 \mathrm{~kJ} \cdot \mathrm{mol}^{-1} & -120 \mathrm{~kJ} \cdot \mathrm{mol}^{-1} & +65.3 \mathrm{~kJ} \cdot \mathrm{mol}^{-1} \
\hline
\end{array}$ Which of these liquids is (are)Thermodynamically stable?
A) 2 and 4
B) 2 and 3
C) 1, 3, and 5
D) 1
E) 3

Question

Quizplus · Accepted Answer

Thermodynamically stable compounds have negative standard free energies of formation. In this list, only methanol (CH3OH) and hydrogen peroxide (H2O2) have negative values, indicating they are thermodynamically stable.

Consider the Following Compounds and Their Standard Free Energies of Formation