Question

How do you find the equilibrium constant for the reverse reaction of this problem?

Given :
Temperature : 1500 degrees Celcius
Equilibrium Constant : 0.1764
Balanced equation: `CO + 3 H_2 = CH_4 + H_2O`

Need:
Equilibrium Constant for `CH_4 + H_2O = CO + 3H_2`

Answer 1

`K'=5.670`

Explanation:

The equilibrium constant for the reaction:

`CO+3H_2rightleftharpoons CH_4+H_2O`

is written as:

`K=([CH_4][H_2O])/([CO][H_2]^3)=0.1764`

The equilibrium constant for the opposite reaction:

`CH_4+H_2OrightleftharpoonsCO+3H_2`

is written as:

`K'=( [CO][H_2]^3)/([CH_4][H_2O])=1/K=1/(0.1764)=5.670`

Here is a video that explains this topic in details:
Chemical Equilibrium | The Equilibrium Conditions.