Question

Hydrogen is used as a rocket fuel because it is very light and reacts explosively and completely with oxygen. For the combustion reaction2H2(g)+O2(g)⇌2H2O(g)what is the likely magnitude of the equilibrium constant K?

Answer 1

Answer:

The magnitude of the equilibrium constant K is likely to be large and positive.

Explanation:

The equilibrium constant (Keq) of a chemical reaction is the ratio of the concentration or pressure of the products to the concentration or pressure of the reactants.

Keq =  [H₂0]² / [H₂]² [O₂]

A large positive value of the Equilibrium constant indicates that at equilibrium more of the products are formed than the reactants (that is the concentration/pressure of the products is higher than the reactants) while a negative equilibrium constant indicates that at equilibrium more of the reactants are present.

As the reaction is explosive and goes to completion, more of the products (H₂O) would be formed at equilibrium and the value of the equilibrium constant would likely be large.

Answer 2

Answer:

The likely magnitude of the equilibrium constant k for the reaction between hydrogen and oxygen is k>10³

Explanation:

The equilibrium constant k for the reaction 2H₂(g) + O₂(g)⇄ 2H₂O(g) can be expressed as follows

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

As the concentration of the products increase and concentration of the reagents decrease, the value of the equilibrium constant increases as well. The reaction between Hydrogen and Oxygen is violent, meaning that the concentration of the products will be high and the concentration of the reagents will be low. That's why the equilibrium constant has a likely magnitude of k>10³