Question

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

Answer 1

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
[CH₃OH]= 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.