Question

A concentrated solution of compound A in the same solvent was diluted from an initial volume of 2.00 mL to a fi nal volume of 25.00 mL and then had an absorbance of 0.733. What is the concentration of A in the concentrated solution?

Answer 1

Answer:

The concentration of A in the concentrated solution is 0.05864

Explanation:

Given

Volume 1 = V1 = 2.00mL

Volume 2 = V2 = 25.00mL

Absorbance 1 = A1 = ?

Absorbance 2 = A2 = 0.733

Beer's law states that the concentration of a chemical solution is directly proportional to its absorbance.

i.e.

V = kA where V = Volume (Concentration)

A = Absorbance

k = Constant

Make k the subject of formula

k = V/A

V1/A1 = V2/A2

Make A1 the subject of the formula

A1 = V1 * A2/V2

Substitute the values of V1, A2 and V2

A1 = 2 * 0.733/25

A1 = 0.05864

So, the concentration of A in the concentrated solution is 0.05864