Question

A calibration curve relating absorbance(y) to concentration (x, measured in mol/L) of y= 0.36x-0.011 Use the calibration curve to determination of the concentration of a solution with an absorbance of 0.02.

Answer 1

The concentration is 0.025 M.

Step-by-step explanation:

We will use beer law to find the concentration.

A = εmCl

This law relate to the linear equation Y = mx + b in following way,

A = y = absorbance

m = εm = slope or extinction coefficient in beer law.

x = c = concentration

and l is length which is 1 cm

Thus equation can be written as,

A = εmc + b

A - b / εm = c

in order to find the concentration we will abstract the intercept from absorbance and then divide it by the slop.

0.02 - 0.011 / 0.36 = c

c =0.009

c = 0.025 M.