Question

uppose a system consists of 50 mg of organic compound dissolved in 1.00 mL of water (solvent 1). Compare the effectiveness of one 1.5-mL extraction versus three 0.5-mL extractions with ether (solvent 2) where the distribution coefficient, K, is equal to 10. Which is more effective

Answer 1

Answer: the more effective is using three 0.5-mL extractions with ether

Explanation:

Using 1.5 ml of ether

Q = [Vaq/(K×Vorg +Vaq)]^n

Q= remaining fraction

Vaq= volume of aqueous phase

Vorg= volume of organic phase

K= distribution coefficient

Using 1.5 ml ether once

Vaq= 1ml, K= 10, n=1

Q = [Vaq/(K×Vorg +Vaq)]^n

Q= [1/10×1.5+1)]^1 = 0.0625

Using 0.5ml ether 3 times

Q = [1/(10×0.5 +1)]^3= 0.0046

Hence using 0.5ml of ether 3 times is more effective