Question

For the reaction 2 H 2 O ( g ) − ⇀ ↽ − 2 H 2 ( g ) + O 2 ( g ) the equilibrium concentrations were found to be [ H 2 O ] = 0.250 M , [ H 2 ] = 0.330 M , and [ O 2 ] = 0.800 M . What is the equilibrium constant for this reaction?

Answer 1

Answer: The equilibrium constant for the given reaction is 4.224

Explanation:

We are given:

Equilibrium concentration of water = 0.250 M

Equilibrium concentration of hydrogen gas = 0.330 M

Equilibrium concentration of oxygen gas = 0.800 M

For the given chemical reaction:

$2H_2O(g)\rightleftharpoons H_2(g)+O_2(g)$

The expression of $K_{eq}$ for above reaction follows:

$K_{eq}=\frac{[H_2][O_2]}{[H_2O]^2}$

Putting values in above expression, we get:

$K_{eq}=\frac{0.330\times 0.800}{(0.250)^2}\\\\K_{eq}=4.224$

Hence, the equilibrium constant for the given reaction is 4.224