Q. Depression in freezing point is 6 K for NaCl solution if $k_{f}$ for water is 1.86 K/kg mol, amount of NaCl dissolved in 1 kg water is
A) 3.42
B) 1.62
C) 3.24
D) 1.71
Explanation
(b)
$\mathrm{\Delta}T_{f} = i \times k_{f} \times \frac{n}{W} \times 1000$
6=2$\times 1.86 \times \frac{n}{1} \times 1$
$\ \ \ \ \ n = \frac{6}{2 \times 1.86} = 1.62$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.