Dinitrogen tetraoxide, a colorless gas, exists in equilibrium with nitrogen dioxide, a reddish brown gas. One way to represent this equilibrium is:
N2O4(g)> 2NO2(g)
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Indicate whether each of the following statements is true or false
At equilibrium at a fixed temperature, we can say that:
1. The concentration of NO2 is equal to the concentration of N2O4.
2. The rate of dissociation of N2O4 is equal to the rate of formation of N2O4.
3. The rate constant for the forward reaction is equal to the rate constant of the reverse reaction.
4. The concentration of NO2 divided by the concentration of N2O4 is equal to the same constant (regardless of initial concentrations)

Explanation:

N2O4(g)  <> 2NO2(g)

Before proceeding,

A chemical equilibrium can be defined as a condition in the course of a reversible chemical reaction in which no net change in the amounts of reactants and products occurs.

Statement 1.

This statement is false. Equilibrium is not about equal concentrations but rather zero change in concentration of the reactants and products.

Statement 2.

This statement is True in chemical equilibrium; the forward and reverse reactions occur at equal rates.

Statement 3.

This statement is False. The rate constant for the forward reaction is not equal to the rate constant of the reverse reaction.

Statement 4.

The concentration of NO2 divided by the concentration of N2O4 is NOT equal to a constant. To obtain a constant value irregardless of the concentrations, the concentration of NO2 must be squared. This comes from the stoichiometry of the reaction

Kc= [NO2]2 / [N2O4]

This statement is false.