Question

A) if the absorbance of .251M copper(II) chloride solution is .456, what is the Beer’s Law extinction coefficient if quvette diameter is 1cm?

B) concentrated acetic acid is 17.5M; vinegar is .870M acetic acid. How much concentrated acetic acid in liters will you need to make 28L of vinegar?

Answer 1

A) Given A= 0.456 C = 0.251 M b = 1cm

Formula of absorbance is

A = εbC

A = absorbance
ε = molar extinction coefficient
b = cell length of cuvette
C = concentration

ε = bC / A = 0.251 x 1 / 0.456

ε = 0.5504 is Beer’s Law extinction coefficient

B)Given actual concentration of Acetic acid C₁= 17.5 M

Concentration of vinegar acetic acid C₂ =0.870M and

volume of Vinegar Acetic acid V₂ = 28 L i.e. = 28000 mL

so we have calculate V₁ =?

So volume calculated by using formula

C₁V₁ = C₂V₂

17.5 x V₁ = 28000 x 0.870

V₁ = 1392 mL i.e. =1.392 L

Volume of 1392 mL used to prepare 28 L of 0.870M vinegar acetic acid.