A sample of a drug C_(21)_(23)O_(3)N (mol. Wt. =369) mixed with lactose C_(12)H_(22)O_(11) (mol.wt.=342) was analysed by osmotic pressure measurement to determine the amount of sugar present . If 100mL of solution containing 1.0g of the drug-sugar mixture has an osmotic pressure of 5.27mmHg at 25^(@)C , what is the per cent sugar present ?

A sample of a drug C_(21)_(23)O_(3)N (mol. Wt. =369) mixed with lactos

1.	A sample of a drug C_(21)_(23)O_(3)N (mol. Wt. =369) mixed with lactose C_(12)H_(22)O_(11) (mol.wt.=342) was analysed by osmotic pressure measurement to determine the amount of sugar present . If 100mL of solution containing 1.0g of the drug-sugar mixture has an osmotic pressure of 5.27mmHg at 25^(@)C , what is the per cent sugar present ?
Answer» SOLUTION :Let the amount of lactose be `xg`. `:.` moles of the SUGAR and drug MIXTURE `=(x)/(342)+((1-x))/(369)` Now, osmotic pressure `=cRT` `(527)/(760)=[{(x)/(342)+((1-x))/(369)}xx(1000)/(100)]xx0.0821xx298` `x=0.580g` `:.` PERCENTAGE of sugar `=58.0%`