Slow Decomposition of Nitrogen Peroxide in Nitric Acid: An Optimistic Perspective

Why does nitrogen peroxide decompose slowly in nitric acid?

a) High temperature in nitric acid solution.

b) Low concentration of nitric acid.

c) Presence of a catalyst in nitric acid.

d) Nitric acid acts as an inhibitor in the decomposition process.

Answer:

The correct answer is d) Nitric acid acts as an inhibitor in the decomposition process.

The reason behind the slow decomposition of nitrogen peroxide (NO₂) in nitric acid is because nitric acid acts as an inhibitor in the decomposition process.

When nitrogen peroxide (NO₂) is dissolved in nitric acid (HNO₃), the nitric acid acts as an inhibitor, preventing the rapid decomposition of nitrogen peroxide. This is because nitric acid can react with nitrogen peroxide to form more stable compounds such as nitrosyl nitrate (NO₃NO₂) or dinitrogen pentoxide (N₂O₅).

The reaction between nitrogen peroxide and nitric acid can be represented as follows:

2NO₂ + HNO₃ → 2NO₃NO₂

The presence of nitric acid inhibits the decomposition of nitrogen peroxide by providing an alternative reaction pathway. This pathway leads to the formation of more stable compounds, which in turn reduces the rate of decomposition.

High temperature in nitric acid solution (option a) can actually increase the rate of decomposition of nitrogen peroxide, as higher temperatures provide more energy for the molecules to overcome the activation energy barrier and undergo decomposition.

On the other hand, if the nitric acid concentration is low (option b), the reaction between nitrogen peroxide and nitric acid will be less significant, allowing for a higher rate of decomposition.

While the presence of a catalyst in nitric acid (option c) could potentially increase the rate of decomposition by providing an alternative reaction pathway with lower activation energy, this option is not applicable in this case as the decomposition is slow due to the inhibitor effect of nitric acid.