Chapter 10.1, Problem 3PP

Interpretation Introduction

Interpretation:

The number of formula unit present in $\text{3}\text{.25 mol}$ of ${\text{AgNO}}_3$ needs to be determined.

Concept introduction:

In 1 mol of any substance, there are $6.022\times {10}^{23}$ units of that substance. These units can be atoms and molecules. The number of units in 1 mol of any substance is known as Avogadro’s number. It is denoted by symbol N_A.

Answer to Problem 3PP

The number of formula units of ${\text{AgNO}}_{\text{3}}$ present in 3.25 mol is $1.96\times {10}^{24}$.

Explanation of Solution

Given information:

The number of moles of ${\text{AgNO}}_{\text{3}}$ is 3.25 mol.

Calculation:

The number of moles can be converted into number of units using the following conversion factor:

$\begin{array}{l}1{\text{ mole = N}}_{\text{A}}\\ \text{1 mole = 6}\text{.022}\times {\text{ 10}}^{23}\text{ units}\end{array}$

Thus, in $\text{3}{\text{.25 mol of AgNO}}_{\text{3}}$, the number of ${\text{AgNO}}_{\text{3}}$ units can be calculated as follows:

$N=n\times N_A$

Putting the values,

$\begin{array}{l}N=\left(3.25\text{ mol}\right)\left(6.022\times {10}^{23}\text{ units/mol}\right)\\ =1.96\times {10}^{24}\text{ units}\end{array}$

Conclusion

Thus, the number of formula units of ${\text{AgNO}}_{\text{3}}$ present in 3.25 mol is $1.96\times {10}^{24}$.