Chapter 4, Problem 4.35QP

Interpretation Introduction

Interpretation: The decrease in the absorbance on dilution, the initial volume and the initial concentration of the solution of copper ion is given. The volume of the water added to the solution is to be determined.

Concept introduction: The absorbance of the solution is given by the formula,

$\text{Absorbance}=\text{Molar}\text{absorptivity}\times \text{Path}\text{length}\times \text{Molar}\text{concentration}$

Thus, absorbance is directly proportional to the concentration of the solution for the given path length.

Therefore,

$\frac{\text{Final}\text{concentration}}{\text{Initial}\text{concentration}}=\frac{\text{Absorbance}\text{of}\text{final}\text{concentration}}{\text{Absorbance}\text{of}\text{initial}\text{concentration}}$

The final volume of the solution is calculated as,

$\text{Final}\text{volume}=\frac{\text{Initial}\text{molar}\text{concentration}\times \text{Initial}\text{volume}}{\text{Final}\text{molar}\text{concentration}}$

To determine: The volume of the water added to the solution of copper ion.