For the Reaction CuS(s) + H₂(g) $\leftrightharpoons$ H₂S(g) + Cu(s) $\Delta$ G ^$\circ$

Multiple Choice

For the reaction CuS(s) + H₂(g) $\leftrightharpoons$ H₂S(g) + Cu(s) ,
$\Delta$ G ^$\circ$ _f (CuS) = -53.6 kJ/mol
$\Delta$ G ^$\circ$ _f (H₂S) = -33.6 kJ/mol
$\Delta$ H ^$\circ$ _f (CuS) = -53.1 kJ/mol
$\Delta$ H ^$\circ$ _f (H₂S) = -20.6 kJ/mol
Calculate the value of the equilibrium constant (K_p) at 798 K and 1 atm pressure.

A) 1.77
B) 1.57
C) 1.37
D) 1.17
E) None of the above