Answer to Question #105960 in Physics for Roopali jha

Question

While using a UV-Vis spectroscopy for concentration of the analyte of 0.11 and 0.21 mM, the absorbance read are 2 and 3 units receptively. What is the concentration if the absorbance read is 2.6 units

Answer 1

Assuming linear dependence of concentration C on the absorbance A, we can write the linear equation:

$$\frac{C-C_1}{C_2-C_1}=\frac{A-A_1}{A_2-A_1},\\ \space\\ \frac{C-0.11}{0.21-0.11}=\frac{A-2}{3-2},$$

express C(A):

$$C(A)=0.1A-0.09,\\ C(2.6)=0.17\text{ mM}.$$