150 g of acetic acid was contaminated with 1 | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(C) Step $1$: Calculate the moles of ascorbic acid $(C_{6}H_{8}O_{6})$.$n = \frac{	ext{mass}}{	ext{molar mass}} = \frac{10.2 \ g}{176 \ g \ mol^{-1}

Vedclass · Accepted Answer

$15$

Vedclass · Answer

(C) Step $1$: Calculate the moles of ascorbic acid $(C_{6}H_{8}O_{6})$.$n = \frac{	ext{mass}}{	ext{molar mass}} = \frac{10.2 \ g}{176 \ g \ mol^{-1}} \approx 0.05795 \ mol$.Step $2$: Calculate the molality $(m)$ of the solution.$m = \frac{	ext{moles of solute}}{	ext{mass of solvent in kg}} = \frac{0.05795 \ mol}{0.150 \ kg} \approx 0.3863 \ mol \ kg^{-1}$.Step $3$: Calculate the depression in freezing point $(\Delta T_{f})$.$\Delta T_{f} = K_{f} 	imes m = 3.9 \ K \ kg \ mol^{-1} 	imes 0.3863 \ mol \ kg^{-1} \approx 1.5066^{\circ} C$.Step $4$: Express $\Delta T_{f}$ in the form $(x 	imes 10^{-1})^{\circ} C$.$1.5066 \approx 15.066 	imes 10^{-1}$.Rounding to the nearest integer,$x = 15$.

$150 \ g$ of acetic acid was contaminated with $10.2 \ g$ ascorbic acid $(C_{6}H_{8}O_{6})$ to lower its freezing point by $(x \times 10^{-1})^{\circ} C$. The value of $x$ is (Nearest integer). [Given $K_{f} = 3.9 \ K \ kg \ mol^{-1}$; Molar mass of ascorbic acid $= 176 \ g \ mol^{-1}$]

Similar Questions

Which of the following will have the highest freezing point $(F.P.)$ at one atmosphere?

$0.05 \ mol$ of a non-volatile solute is dissolved in $500 \ g$ of water. What is the depression in freezing point of the resultant solution (in $K$)? $(K_f(H_2O) = 1.86 \ K \ kg \ mol^{-1})$

Bromoform has a normal freezing point of $7.734^{\circ} C$ and its $K_{f} = 14.4^{\circ} C / m$. $A$ solution of $2.60 \ g$ of an unknown substance in $100 \ g$ of bromoform freezes at $5.43^{\circ} C$. What is the molecular weight of the unknown substance?

The freezing point of a $0.05 \ molal$ solution of a non-electrolyte in water is $.......... \ ^oC$. $(K_f = 1.86 \ K \ kg \ mol^{-1})$

What is the relation between the depression in freezing point and the molar mass of a non-volatile solute?

Vedclass Test Series

Exam Paper Generator

Online Exam Module