Chapter 4, Problem 77PS

(a)

Interpretation Introduction

Interpretation:

By using the given absorbance and concentration values a calibration plot has to be constructed and slope and intercept has to be determined from the calibration plot.

Concept introduction:

• Spectrophotometry is the interaction between light and matter that provides quantitative about solution concentration.
• Absorbance (A): it is the negative logarithm of transmittance of the sample taken. And its value increases as the concentration increases.

  $\text{Absorbance}\text{=}\text{-}\text{log}\text{T}\text{=}\text{-}\text{log}\frac{\text{P}}{{\text{P}}_{\text{0}}}$

T is the transmittance and it is the ratio of the amount of light transmitted by or passing through the sample (P) relative to the light that initially fell on the sample.

        $\text{Transmittance}\text{(T)}=\frac{\text{P}}{{\text{P}}_{\text{0}}}=\frac{\text{Intencity}\text{of}\text{transmitted}\text{light}}{\text{Intencity}\text{of}\text{incident}\text{light}}$

• $\text{y}\text{=}\text{mx+c}$ is a straight line equation where m is the slope and c is the intercept.
• Concentration of the solution can be expressed in many ways; molarity is one of the important parameter to express the concentration of solution. And it is a measure of the concentration of a solute in a solution.

(b)

Interpretation Introduction

Interpretation:

The concentration of the solution with absorbance (A) $0.52$  has to be calculated.

Concept introduction:

• Spectrophotometry is the interaction between light and matter that provides quantitative about solution concentration.
• Absorbance (A): it is the negative logarithm of transmittance of the sample taken. And its value increases as the concentration increases.

  $\text{Absorbance}\text{=}\text{-}\text{log}\text{T}\text{=}\text{-}\text{log}\frac{\text{P}}{{\text{P}}_{\text{0}}}$

T is the transmittance and it is the ratio of the amount of light transmitted by or passing through the sample (P) relative to the light that initially fell on the sample.

        $\text{Transmittance}\text{(T)}=\frac{\text{P}}{{\text{P}}_{\text{0}}}=\frac{\text{Intencity}\text{of}\text{transmitted}\text{light}}{\text{Intencity}\text{of}\text{incident}\text{light}}$

• $\text{y}\text{=}\text{mx+c}$ is a straight line equation where m is the slope and c is the intercept.
• Concentration of the solution can be expressed in many ways, molarity is one of the important parameter to express the concentration of solution.  And it is a measure of the concentration of a solute in a solution.