Change in Free Energy

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

For the reaction above, what is the sign and value of entropy for the reaction, given:

H$_2$ (g), S$^\circ$(at 25$^\circ$C) = 130.7 J/(mol*K)

N$_2$ (g), S$^\circ$(at 25$^\circ$C) = 191.56 J/(mol*K)

NH$_3$ (g), S$^\circ$(at 25$^\circ$C) = 192.77 J/(mol*K)

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

What is the standard free energy change, $\triangle$G$^\circ$, for the following reaction at 298 K? Is the reaction spontaneous?

2 PCl$_3$ (g) + O$_2$ (g) $\longrightarrow$ 2 POCl$_3$, $\triangle$H = - 620.6 kJ/mol

Values of standard molar entropy, S$_{f}^\circ$ are as follows: 2 PCl$_3$ (g), 311.8 J/K; O$_2$ (g), 205.1 J/K; POCl$_3$, 222.4 J/K