Chapter 12, Problem 12.1P

Interpretation Introduction

Interpretation:

Molarity of a saturated solution of ${\text{NaHCO}}_{\text{3}}$ has to be calculated.

Concept Introduction:

The formula to evaluate molarity is given as follows:

  $M=\frac{n}{V}$

Here,

$M$ denotes molarity.

$n$ denotes number of moles.

$V$ denotes volume.

Answer to Problem 12.1P

Molarity of a saturated solution of ${\text{NaHCO}}_{\text{3}}$ is $0.82136\text{ mol/L}$.

Explanation of Solution

The formula to convert mass in grams to moles is as follows:

  $\text{Number of moles}=\frac{\text{Given mass}}{\text{molar mass}}$        (1)

Substitute $\text{69}\text{.0 g}$ for mass and $\text{84}\text{.007 g/mol}$ for molar mass of ${\text{NaHCO}}_{\text{3}}$ to calculate the moles of ${\text{NaHCO}}_{\text{3}}$ in equation (1).

  $\begin{array}{c}\text{Number of moles}=\frac{\text{69}\text{.0 g}}{\text{84}\text{.007 g/mol}}\\ =0.82136\text{ mol}\end{array}$

The formula to evaluate molarity is given as follows:

  $M=\frac{n}{V}$        (2)

Substitute $0.82136\text{ mol}$ for $n$ and $1\text{ L}$ for $V$ in equation (2).

  $\begin{array}{c}M=\frac{0.82136\text{ mol}}{1\text{ L}}\\ =0.82136\text{ mol/L}\end{array}$