If a `6.84%`(wt,vol.)solutionof cane sugar(mol.Wt.=`342`)is isotonic with `1.52%(wt.//vol.)`solution of thiocarbamide ,then the molecular weight of thiocarbamide is

Options

A. 152
B. 76.5
C. 85.5
D. 180

Answer

C

Explanation

For two nonelectrolytic solution, if isotonic, then `C_(1) =C_(2)`
`(W_(1) xx 1000)/(M_(1) xx V_(1)) = (W_(2) xx 1000)/(M_(2) xx V_(2))`
` :. (6.08 xx 1000)/(342 xx 100) = (1.52 xx 1000)/(M_(2) xx 100)`
`6.08/342=1.52/M_(2) :. M_(2) = (1.52 xx 342)/6.08 = 85.5`