Question

Use bond energies (Table) to show that the preferred products for the decomposition of_{${\mathbf{\text{N}}}_{\mathbf{2}}{\mathbf{\text{O}}}_{\mathbf{3}}$}are${\mathbf{\text{NO}}}_{\mathbf{2}}$and_{$\mathit{N}\mathit{O}$}rather than${\mathit{O}}_{\mathbf{2}}$and_{${\mathbf{\text{N}}}_{\mathbf{2}}\mathbf{\text{O}}$}. (The_{$\mathbf{N}\mathbf{-}\mathbf{O}$}single bond energy is$\mathbf{201}\mathbf{}\mathit{k}\mathit{J}\mathbf{/}\mathit{m}\mathit{o}\mathit{l}$.) (Hint: Consider the reaction kinetics.)

Short answer

The preferred products in the decomposition of ${\text{N}}_2{\text{O}}_3$are $N{O}_2$ and $NO$ because they require less activation energy to form.

Step-by-step solution

Define balanced reactions

To balance a reaction, the number of atoms on both the reactants and products sides must be the same. Coefficients must be added to the chemical equation to do this.

The first balanced decomposition equation of ${\text{N}}_2{\text{O}}_3$ which produces${\text{NO}}_2$ and_$NO$ is as follows:

${\text{N}}_2{\text{O}}_3\to {\text{NO}}_2+\text{NO}$

The second decomposition equation of _{${\text{N}}_2{\text{O}}_3$} which produces $O_2$ and _{$N_{2}O$} is as follows:

_{${\text{N}}_2{\text{O}}_3\to {\text{O}}_2+{\text{N}}_2\text{O}$}

Energy required to break N-N  bond

For reaction (a), observe the figure that the reaction must involve the breaking of the $N-N$ single bond.

It requires about $160kJ/mol$energy to break an $N-N$single bond.

Energy required to break N=O  bond

For reaction (b), observe the figure that the reaction must involve the breaking of the $N=o$ bond.

Even for an $N-O$ single bond, the activation energy required to break it is _$201kJ/mol$.

Preferred products formed for the reaction:

The preferred products for the decomposition of${\text{N}}_2{\text{O}}_3$are${\text{NO}}_2$andrather than $O_2$ and ${\text{N}}_2\text{O}$, because from the activation energies of the two decomposition reactions, the activation energy for breaking the N-N bond is less than that of the$N=o$bond.

The favored products are${\text{NO}}_2$and $NO$, since they requirelessactivation energy to form.