Question

18-19. If a sample for spectrophotometric analysis is placed in a 10-cm cell, the absorbance will be 10 times greater than the absor- bance in a 1-cm cell. Will the absorbance of the reagent-blank solu- tion also be increased by a factor of 10?\

Answer 1

Answer:

As long as it is a blank solution of the reagent, the Absorbance will be 0 regardless of the path length.

Explanation:

Absorbance of light by a reagent of concentration c, is given as

A = εcl

A = Absorbance

ε = molar absorptivity

c = concentration of reagent.

l = length of light path or length of the solution the light passes through.

So, if all.other factors are held constant, If a sample for spectrophotometric analysis is placed in a 10-cm cell, the absorbance will be 10 times greater than the absorbance in a 1-cm cell.

But the reagent blank solution is called a blank solution because it lacks the given reagent. A blank solution does not contain detectable amounts of the reagent under consideration. That is, the concentration of reagent in the blank solution is 0.

Hence, the Absorbance is subsequently 0. And increasing or decreasing the path length of light will not change anything. As long as it is a blank solution of the reagent, the Absorbance will be 0 regardless of the path length.

Hope this Helps!!!