Chapter 17, Problem 80A

Interpretation Introduction

Interpretation:

The molar concentration of benzaldehyde is to be calculated at a given temperature.

Concept introduction:

The molar concentration is defined as the moles of a solute per volume of total solution.

$\text{M=}\frac{\text{n}}{\text{V}}$

Where, n = number of moles of solute

V = volume of the solution in liters

Answer to Problem 80A

The molar concentration of ${\text{C}}_{\text{7}}{\text{H}}_{\text{6}}\text{O}$ is $\text{9}\text{.8mol/L}$

Explanation of Solution

Given information : the density of the ${\text{C}}_{\text{7}}{\text{H}}_{\text{6}}\text{O = 1}\text{.043 g/mL}$

The molar concentration is defined as the moles of a solute per volume of total solution.

$\text{M=}\frac{\text{n}}{\text{V}}$

Where, n = number of moles of solute

V = volume of the solution in liters

Firstly, density is converted in to g/L by multiplying ${\text{10}}^{\text{3}}$

So, density $\text{=1}{\text{.043×10}}^{\text{3}}\text{g/L}$

Molecular weight of ${\text{C}}_{\text{7}}{\text{H}}_{\text{6}}\text{O}$ is $\text{106}\text{.12g/mol}$

Now to calculate the molar concentration, density is dividing by the molecular weight of ${\text{C}}_{\text{7}}{\text{H}}_{\text{6}}\text{O}$

Molar concentration is

$\begin{array}{l}\text{=}\frac{\text{1}{\text{.043×10}}^{\text{3}}}{\text{106}\text{.12}}\\ \text{=0}{\text{.0098×10}}^{\text{3}}\\ \text{=9}\text{.8 mol/L}\end{array}$

The molar concentration of ${\text{C}}_{\text{7}}{\text{H}}_{\text{6}}\text{O}$ is $\text{9}\text{.8mol/L}$

Conclusion

The molar concentration of ${\text{C}}_{\text{7}}{\text{H}}_{\text{6}}\text{O}$ is $\text{9}\text{.8mol/L}$