Hydrogen is used as a rocket fuel because it is very light and reacts explosively and completely with oxygen. For the combustion reaction 2H2(g)+O2(g)⇌2H2O(g) what is the likely magnitude of the equilibrium constant K?
1. K<10−3
2. 10−3 3. K=0
4. K>103

1. K<10−3

Explanation:

Equilibrium Constant is an expression which involves the concentration of the product divided by the concentration of the reactant molecules.

However the concentration of the pure liquid and pure solid is regarded as 1.

Equilibrium expression for the equation 2H2(g)+O2(g)⇌2H2O(g)

Equilibrium Constant = [H2O]^2/[H2]^2 x [O2]

Since H2O is a pure liquid, its concentration = 1

There fore;

Equilibrium Constant = 1/[H2]^2 x [O2]

This shows that the Equilibrium Constant of the equation will be less than 1 and greater than 0.