Question

For the reaction

N2(g) + O2(g)→2 NO(g) H° = 181 kJ and S° = 24.9 J/K G°

The equilibrium constant, K, would be greater than 1 at temperatures (above or below)._____. _______ Kelvin.

Answer 1

Answer: The equilibrium constant, K, would be greater than 1 at temperatures above 7269 Kelvin.

Explanation:-

Using Gibbs Helmholtz equation:

`\Delta G=\Delta H-T\Delta S`

Where: T= Temperature =

`\Delta H` = enthalpy change = 181 kJ/mol = 181000 J/mol (1kJ=1000J)

`\Delta S` = entropy change= 24.9 J/Kmol

The Gibbs free energy is related to equilibrium constant by following relation:

`\Delta G=-2.303RTlog K`

K > 1, when
`\Delta G<0`

Putting the values in the equation:

For
`\Delta G`< 0,
`T\Delta S` >
`\Delta H`

`T* 24.9>181000`

`T>7269K`

Thus the equilibrium constant, K, would be greater than 1 at temperatures above 7269 Kelvin.