Question

Which answer does not describe the following reaction? NO (g) + O2 (g) Two arrows stacked on top of each other. The top arrow points to the right. The bottom arrow points to the left. 2 NO2 (g)
(1) The reaction is in dynamic equilibrium.
(2)The reaction does not go to completion.
(3)The reaction is reversible.
(4)The concentration of reactants and products will be equal.

Answer 1

“(4) The concentration of reactants and products will be equal” does not describe the reaction.

2NO(g) + O₂(g) ⇌ 2NO₂(g)

The concentrations will almost certainly not be equal.

The reaction is a reversible dynamic equilibrium. There is always some NO and NO₂ present at equilibrium, so the reaction does not go to completion.

Answer 2

Answer: Option (2) is the correct answer.

Explanation:

Dynamic equilibrium is an equilibrium where rate of forward and reversible reactions are equal.

For example, $NO(g) + O_{2}(g) \rightleftharpoons 2NO_{2}$

This reaction show rate at which reactants are combining is equal to the rate of formation of nitrogen dioxide.

Also, here the concentration of reactants is equal to the concentration of products.

Thus, we can conclude that out of the given options the reaction does not go to completion does not describe the given reaction.