Lawrie Ryan and Roger Norris Solutions for Chapter: Entropy and Gibbs Free Energy, Exercise 11: Question

Calculate the standard Gibbs free energy change of reaction in the following reaction using the standard molar values for Gibbs free energy change given here. Comment on whether the reaction is Spontaneous or not, under standard conditions.

$2{\mathrm{H}}_2{\mathrm{O}}_2\left(\mathrm{l}\right)\to 2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)+{\mathrm{O}}_2\left(\mathrm{g}\right)$

Values for

 $$\begin{gathered} {\mathrm{G}}^{⊝} \mathrm{in} \mathrm{kJ} {\mathrm{mol}}^{-1}; \\ {\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)=-273.2 \\ {\mathrm{O}}_2\left(\mathrm{g}\right)=0(\mathrm{As} \mathrm{it} \mathrm{is} \mathrm{their} \mathrm{in} \mathrm{standard} \mathrm{states}) \\ {\mathrm{H}}_2{\mathrm{O}}_2\left(\mathrm{l}\right)=-120.4. \end{gathered}$$

Calculate the standard Gibbs free energy change of reaction in the following reaction using the standard molar values for Gibbs free energy change given here. Comment on whether the reaction is Spontaneous or not, under standard conditions.

${\mathrm{NH}}_4{\mathrm{NO}}_3\left(\mathrm{s}\right)\to {\mathrm{N}}_2\mathrm{O}\left(\mathrm{g}\right)+2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{g}\right)$

Values for

$$\begin{gathered} {\mathrm{G}}^{⊝} \mathrm{in} \mathrm{kJ} {\mathrm{mol}}^{-1}; \\ {\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)=-273.2 \\ {\mathrm{N}}_2\mathrm{O}\left(\mathrm{g}\right)=+104.2 \\ {\mathrm{NH}}_4{\mathrm{NO}}_3=-184.0. \end{gathered}$$

Calculate the standard Gibbs free energy change of reaction in the following reaction using the standard molar values for Gibbs free energy change given here. Comment on whether the reaction is Spontaneous or not, under standard conditions.

$2\mathrm{Mg}\left(\mathrm{s}\right)+{\mathrm{O}}_2\left(\mathrm{g}\right)\to 2\mathrm{MgO}\left(\mathrm{s}\right)$

Values for

$$\begin{gathered} {\mathrm{G}}^{⊝} \mathrm{in} \mathrm{kJ} {\mathrm{mol}}^{-1}; \\ \mathrm{MgO}\left(\mathrm{s}\right)=-569.4 \\ \mathrm{Mg}\left(\mathrm{s}\right)=0 \\ {\mathrm{O}}_2\left(\mathrm{g}\right)=0. \end{gathered}$$

Calculate the standard Gibbs free energy change of reaction in the following reaction using the standard molar values for Gibbs free energy change given here. Comment on whether the reaction is Spontaneous or not, under standard conditions.

${\mathrm{C}}_3{\mathrm{H}}_8\left(\mathrm{g}\right)+5{\mathrm{O}}_2\left(\mathrm{g}\right)\to 3{\mathrm{CO}}_2\left(\mathrm{g}\right)+4{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)$

Values for

$$\begin{gathered} {\mathrm{G}}^{⊝} \mathrm{in} \mathrm{kJ} {\mathrm{mol}}^{-1}; \\ {\mathrm{CO}}_2\left(\mathrm{g}\right)=-394.4 \\ {\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)=-273.2 \\ {\mathrm{O}}_2\left(\mathrm{g}\right)=0 \\ {\mathrm{C}}_3{\mathrm{H}}_8\left(\mathrm{g}\right)=-23.4. \end{gathered}$$

Calculate the standard Gibbs free energy change of reaction in the following reaction using the standard molar values for Gibbs free energy change given here. Comment on whether the reaction is Spontaneous or not, under standard conditions.

$3 \mathrm{Mg}\left(\mathrm{s}\right)+{\mathrm{Fe}}_2{\mathrm{O}}_3\left(\mathrm{s}\right)\to 3\mathrm{MgO}\left(\mathrm{s}\right)+2\mathrm{Fe}\left(\mathrm{s}\right)$

Values for

$$\begin{gathered} {\mathrm{G}}^{⊝} \mathrm{in} \mathrm{kJ} {\mathrm{mol}}^{-1}; \\ \mathrm{MgO}\left(\mathrm{s}\right)=-569.4 \\ \mathrm{Fe}\left(\mathrm{s}\right)=0 \\ \mathrm{Mg}\left(\mathrm{s}\right)=0 \\ {\mathrm{Fe}}_2{\mathrm{O}}_3\left(\mathrm{s}\right)=-742.2. \end{gathered}$$