Entropy Thermodynamics

N$_2$ (g) + 3 H$_2$ (g) $\leftrightharpoons$ 2 NH$_3$ (g)

For the reaction above what is $\triangle$H$^\circ$ given that $\triangle$H$_f^\circ$ for NH$_3$ (g) is -45.9 kJ/mol at 25$^\circ$C?

N$_2$ (g) + 3 H$_2$ (g) $\leftrightharpoons$ 2 NH$_3$ (g)

For the reaction above, calculate the change in free energy for the reaction, if it were to go to completion.

N$_2$ (g) + 3 H$_2$ (g) $\leftrightharpoons$ 2 NH$_3$ (g)

For the reaction above, calculate the free energy of formation, $\triangle$G$_f^\circ$ for each of the products and reactions.

Calculate the standard free energy change, $\triangle$G$^\circ$, for the following reaction. Is the reaction spontaneous?

CH$_4$ (g) + 2 O$_2$ (g) $\longrightarrow$ CO$_2$ (g) + 2 H$_2$O (l)

Values of standard molar entropy, S$_{f}^\circ$ are as follows: CH$_4$ (g), 186 J/(K*mol); O$_2$ (g), 205 J/(K*mol); CO$_2$ (g), 213.6 J/(K*mol); 2 H$_2$O (l), 69.9 J/(K*mol)

$\triangle$H$^\circ$ for this reaction is -890.3 kJ