A 0.5 molal solution of ethylene glycol in water is used as coolant in a car. If the freezing point depression constant of water is 1.86°C per mole, the mixture shall freeze at

Question

A 0.5 molal solution of ethylene glycol in water is used as coolant in a car. If the freezing point depression constant of water is 1.86°C per mole, the mixture shall freeze at (A) 0.93°C (B) -0.93°C (C) 1.86°C (D) -1.86°C

Tardigrade Admin · Accepted Answer

Depression of freezing point Δ T f = K f m Given that, m =0.5 K f =1.86 K - kg / mole So,Δ T f =1.86 × 0.5 T f =0-0.93=-0.930 C

Q. A 0.5 molal solution of ethylene glycol in water is used as coolant in a car. If the freezing point depression constant of water is 1.86 $^{\circ}$ C per mole, the mixture shall freeze at

0.93 $^{\circ}$ C

-0.93 $^{\circ}$ C

1.86 $^{\circ}$ C

-1.86 $^{\circ}$ C

Depression of freezing point
$Δ T_{f} = K_{f} m$
Given that,
$m = 0.5$
$K_{f} = 1.86 K - k g / m o l e$
So, $Δ T_{f} = 1.86 \times 0.5$
$T_{f} = 0 - 0.93 = - 0.9 3^{0} C$

Q. A 0.5 molal solution of ethylene glycol in water is used as coolant in a car. If the freezing point depression constant of water is 1.86∘C per mole, the mixture shall freeze at

0.93∘C

-0.93∘C

1.86∘C

-1.86∘C