Question

The distribution coefficient, k , 10 for compound y. what weight of compound y would be removed from a solution of 4.0 g of y in 100 ml water by a single extraction with 100 ml of ether?

Answer 1

Answer : The weight of compound y would be removed is  3.6363 g.

Solution :  Given,

Distribution coefficient, K = 10

Volume of ether (organic layer) = 100 ml

Volume of water (aqueous layer) = 100 ml

Total Weight of material dissolved = 4 g

Formula used :

$K=\frac{[Solute]_{o} }{[Solute]_{aq}}=\frac{C_{o} }{C_{aq}}=\frac{W_{o}/V_{o} }{W_{aq}/V_{aq} }$

Where,

'O' repersent for organic layer and 'aq' repersent for aqueous layer.

$C_{o}$ and $C_{aq}$ are the concentration of organic solution and the concentration of aqueous solution respectively.

$W_{o}$ and $W_{aq}$ are the weight of material dissolved in each organic and aqueous layer respectively.

$V_{o}$ and  $V_{aq}$ are the volume of organic and aqueous layer respectively.

Let, the weight of compound y removed '$W_{o}$'  is 'X' gram.

$W_{o}$ = X gram

$W_{aq}$ = Total weight of material - weight of compound y removed = 4 - X gram

Now put all the values in above formula,we get

$K=\frac{W_{o}/V_{o}}{W_{aq}/V_{aq}}$

10= $\frac{\frac{X(g)}{100(ml)} }{\frac{4-X(g)}{100(ml)} }$

Rearranging the terms, we get the value of X, as

X = 3.6363 g