What is its concentration in M?

Question

The equation for the calibration curve of a set of standards is y=4.8571x+0.0038. If a sample of the same solution has an absorbance reading of 0.85, what is its concentration in M? (Only enter numeric value in the answer, do not enter the unit, M.)

 

Answer 1

We have to assume that the values in the standard curve are in M (molarity).

Solving for x in the equation we have...

x = y - 0.0038 / 4.8571

x = 0.85 - 0.0038 / 4.8571

x = 0.8462/4.8571

x = 0.174 = 0.17 M