Question

Sb %T> 30, 34 2) How would a student make 500.0 mL of a o.05200 M solution of irond(II) using a stock solution that is 0.3180 M in iron(II)? Explain how this would be done. 0-3180 Viso-08 18レ 3) A student measures k for a certain blue dye to be 200.4 M' at 560 nm. What is the molarity of the dye in a solution with an absorbance of 0.118 at this wavelength?

Answer 1

Answer for (2)

Formula used is

M₁V₁ = M₂V₂

M₁ = 0.052 M , V₁ = 500 mL , M₂ = 0.318 M , V₂ = ?

Thus V₂ =  M₁V₁ / M₂

=( 0.052 x 500) / (0.318)

= 81.76 mL

Thus, a student is required to take 81.76 mL of Fe(III) solution from stock and make up the volume upto 500 mL to get the resultant solution of 0.052 M.