Question

A solution containing $62\, g$ ethylene glycol in $250 \,g$ water is cooled to $-10^{\circ}C$. If $K_f$ for water is $1.86\, K\, kg \,mol^{-1}$, the amount of water (in g) separated as ice is :

• A. 32
• B. 48
• C. 16
• D. 64

Answer 1

Answer: (D)

64

Answer 2

$\Delta T_f = k_f. m$ $10 = 1.86 \times \frac{62 / 62}{W_{kg}}$ $W = 0.186 \; kg$ $\Delta W = (250 - 186) = 64 \; gm$