For the reaction CO+2H2=CH3OH at 700 K, equilibrium concentrations are [H2]=0.072 M, [CO] = 0.020M, and [CH3OH] = 0.030 M. Calculate K

The balanced equation for the reaction is

CO (g) + 2H₂ (g) ⇄ CH₃OH (g)

The given concentrations are at equilibrium state. Hence we can use them directly in calculation with the expression for the equilibrium constant, k. expression for k can be written as

k = [CH₃OH (g) ] / [CO (g) ] [H₂ (g) ]²

[H₂ ]=0.072 M

[CO] = 0.020M

[CH ₃OH] = 0.030 M

From substitution,

k = 0.030 M / 0.020 M x (0.072 M) ²

k = 289.35 M⁻²

Hence, equilibrium constant for the given reaction at 700 K is 289.35 M ⁻².