Hydrogen and nitrogen react to form ammonia. Which statement best

describes the reactants and product at equilibrium?

A. The concentration of hydrogen and nitrogen equals the ammonia

concentration

B. The concentrations of hydrogen, nitrogen, and ammonia are

stable.

C. Hydrogen and nitrogen have combined to form ammonia.

D. Hydrogen and nitrogen stop reacting to form ammonia,

Hydrogen and nitrogen react to form ammonia. The statement that best describes the reactants and product at equilibrium: (A) The concentration of hydrogen and nitrogen equals the ammonia concentration

Explanation:

Reversible reaction

The reaction that can occur in either way that is the reactants can also form products and the same time products can combine to form reactants back.

That is:

A + B--> C+D

At the same time this reaction also occurs:

C+D-->A + B

In reversible reactions the stage is reached, where concentration of reactants become equal to concentration of products. That stage is called "Equilibrium state ".

In the above asked question : Formation of ammonia is a reversible reaction and in this also equilibrium is achieved where concentration of reactants and products become equal but reaction doesn't stop.