Chapter 3, Problem 8E

(a)

Interpretation Introduction

To determine:

A representation of the product mixture for the reaction between $\text{NO}$ and ${\text{O}}_2$ to form ${\text{NO}}_{\text{2}}$ and the limiting reactant in the reaction.

Interpretation Introduction

In the given diagram, the blue spheres represent $\text{N}$ and the red ones represent $\text{O}$ . It means there are eight $\text{NO}$ molecules and five ${\text{O}}_2$ molecules. The balanced chemical reaction implies that one mole of ${\text{O}}_2$ reacts with two moles of $\text{NO}$ to give two moles of ${\text{NO}}_{\text{2}}$ .

It means $5$ moles of ${\text{O}}_2$ need $10$ moles of $\text{NO}$ to form ten moles of ${\text{NO}}_{\text{2}}$ . But we have $8$ moles of $\text{NO}$ those can react with only $4$ moles of ${\text{O}}_2$ , so one mole ${\text{O}}_2$ could not react. It means in the representation of product mixture there are $8$ moles of ${\text{NO}}_{\text{2}}$ and one mole of ${\text{O}}_2$ .

One molecule of ${\text{NO}}_{\text{2}}$ consists of one atom of $\text{N}$ and three atoms of $\text{O}$ . It means in the representation of ${\text{NO}}_{\text{2}}$ molecule, one $\text{N}$ sphere is attached to two $\text{O}$ spheres and there would be eight such molecules and one molecule of ${\text{O}}_2$ . The representation of product mixture is shown in Figure 1.

Figure 1
One mole ${\text{O}}_2$ could not react in the reaction because $\text{NO}$ gets consumed. A limiting reactant is the one that gets consumed even before completion of the reaction. Hence $\text{NO}$ is the limiting reagent in the reaction.