Q. The empirical formula of a nonelectrolyte is $CH_{2}O.$ A solution containing 3 g of the compound exerts the same osmotic pressure as that of 0.05 M glucose solution. The molecular formula of the compound is
A) $CH_{2}O$
B) $C_{2}H_{4}O_{2}$
C) $C_{4}H_{8}O_{4}$
D) $C_{3}H_{6}O_{3}$
Explanation
(b)
($\pi$) glucose =($\pi$) unknown compound
0.05= $\frac{3}{M}\ \$
$\ \ \ M = \frac{3}{0.05} = 60$
n=$\ \ \frac{60}{30}\ \$=2 (e.f.m. for $CH_{2}O = 30$)
so, molecular formula=$C_{2}H_{4}O_{2}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.