Question

Indicate which of the following statements is true or false.
The reaction between hydrogen and nitrogen to form ammonia is reversible.
A) True
B) False

Answer 1

Hint: The Haber process is the reaction of the production of ammonia by the combination of nitrogen with hydrogen. It is a reversible reaction. The chemical equilibrium is a condition to express the reversible reaction. The nitrogen and hydrogen combine to form ammonia. At high temperatures and pressure, the ammonia decomposes back into corresponding nitrogen and hydrogen.

Complete step by step answer:
Equilibrium is the condition that exists in the reversible reactions. Here the forward and backward reactions occur simultaneously at the same rate.
Chemical reactions that exhibit the equilibrium do not go on the completion of the reaction. Instead of that, the reactions are labelled as the forward and reverse or backward reactions which occur simultaneously. The forward and reverse reactions are the opposite. The reverse reaction is considered as the forward reaction written in a backward manner. One of the best examples is the synthesis of ammonia by Haber’s process.
In forwarding reaction, the nitrogen gas and hydrogen gas react to form ammonia. Reaction as follows:
\[\text{ }{{\text{N}}_{\text{2}}}_{\left( \text{g} \right)}\text{ + 3}{{\text{H}}_{\text{2}}}_{\left( \text{g} \right)}\to \text{ 2N}{{\text{H}}_{\text{3}}}_{\left( \text{g} \right)}\text{ }\]

This forward reaction requires the pressure in the range of 2100 to 3600 psi and temperature between the range of 300 to 550 degrees celcius.At these temperature and pressure conditions, ammonia spontaneously decomposes into nitrogen and hydrogen gas:
\[\text{ 2N}{{\text{H}}_{\text{3}}}_{\left( \text{g} \right)}\text{ }\to \text{ }{{\text{N}}_{\text{2}}}_{\left( \text{g} \right)}\text{ + 3}{{\text{H}}_{\text{2}}}_{\text{(g)}}\text{ }\]

This is the forward and the backward reaction which is of the formation of ammonia and then decomposition of ammonia. These reactions occur simultaneously at the same rate. When this happens the concentrations of nitrogen, hydrogen, and ammonia remain constant and the system is said to be “at equilibrium”. The equilibrium reaction for ammonia is as shown below:
\[\text{ }{{\text{N}}_{\text{2}}}_{\left( \text{g} \right)}\text{ + 3}{{\text{H}}_{\text{2}}}_{\left( \text{g} \right)}\text{ }\rightleftarrows \text{ 2N}{{\text{H}}_{\text{3}}}_{\left( \text{g} \right)}\text{ }\]

Thus, the reaction between hydrogen and nitrogen to form ammonia is reversible.
Therefore, the statement is true. So, the correct answer is “Option A”.

Note: Any change in the concentration, temperature, pressure affects the equilibrium by increasing or decreasing the relative amounts of reactant and product. The equilibrium between the reversible reactions is explained by Le Chatelier’s principle.