For the reaction H 2 (g) + I 2 (g) ⇋ 2HI (g), the standard free energy is ∆ G ⊖ 0. The Equilibrium constant (K ) would be __________.

Question

For the reaction H 2 (g) + I 2 (g) ⇋ 2HI (g), the standard free energy is ∆ G ⊖ > 0. The Equilibrium constant (K ) would be __________.

Philoid · Accepted Answer

• In the viewpoint of thermodynamics, Equilibrium can be explained by the following mathematical equation

∆G = ∆G^⊖ + RTlnQ which comes down to ∆G = ∆G^⊖ + RTlnK and then to

∆G^⊖ = - RTlnK (as at Equilibrium ∆G is zero and K_c is = Q )

And k = e^-^∆^G^⊖ ^/RT (by taking antilog on both sides)

therefore, when ∆G^⊖ > 0, which means positive, it will give a negative K value

( e^G^⊖ ^/RT attains a negative value for a positive ∆G^⊖ ) and hence K < 1.