Chapter 13, Problem 13.7QAP

Interpretation Introduction

(a)

Interpretation:

The absorbance of the solution containing the complex formed between $\text{Bi}\left(\text{III}\right)$ and thiourea having a concentration of $4.25\times {10}^{-5}\text{M}$ and the molar absorptivity of $9.23\times {10}^3\text{L}/\text{mol}\cdot \text{cm}$ is to be calculated.

Concept introduction:

The absorbance of the solution is the ability of the solution to absorb the monochromatic light passing through it. The absorbance of the solution is defined as the ratio of the intensity of light incident on the solution to the intensity of light absorbed by the solution.

The relation between the absorbance, path length, molar absorptivity and the concentration of the solution is given as.

$A=\epsilon bc$

Interpretation Introduction

(b)

Interpretation:

The percent transmittance of the solution formed from the complex between $\text{Bi}\left(\text{III}\right)$ and thiourea is to be calculated.

Concept introduction:

The percent transmittance of a solution is the ability of the solution to allow the monochromatic light to pass through it. The percent transmittance of a solution is the ratio of the intensity of monochromatic light incident on the solution to the intensity transmitted through the solution.

The relation between the absorbance and transmittance is established by the Beer’s law.

$A=-\log T$

Interpretation Introduction

(c)

Interpretation:

The concentration of the solution is to be determined for the change in the path length of the cell containing the solution.

Concept introduction:

The concentration of the solution, path length of the cell and the molar absorptivity of the solution plays an important role in determining the absorbance of the solution. If any of the parameter is affected, it leads to change in the absorbance of the solution.

The relation between the absorbance, path length, molar absorptivity and the concentration of the solution is given as.

$A=\epsilon bc$