A calibration plot of absorbance vs. concentration (ppm) was obtained with standard known Red 40 dye solutions. The slope of the best-fit straight line of the plot is 0.038 ppm- 1 The absorbance of the dilute unknown sports drink was 0.64 What is the concentration of this dilute unknown sports drink ?

16.84 ppm is the concentration of this dilute unknown sports drink.

Explanation:

Using Beer-Lambert's law :

Formula used :

where,

A = absorbance of solution

C = concentration of solution

l = length of the cell

= molar absorptivity of this solution

The graph between A and C gives straight line with positive slope value. the value of slope corresponds to

Slope =

According to question we have;

The absorbance of the dilute unknown sports drink:

A = 0.64

Slope of the graph =

The concentration of the dilute unknown sports drink = C

16.84 ppm is the concentration of this dilute unknown sports drink.