(C) Concentration of $HCOOH = 0.5 \, mL \, L^{-1}$.Mass of $HCOOH = 0.5 \, mL \times 1.05 \, g \, mL^{-1} = 0.525 \, g \, L^{-1}$.Molar mass of $HCOOH

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(C) Concentration of $HCOOH = 0.5 \, mL \, L^{-1}$.Mass of $HCOOH = 0.5 \, mL \times 1.05 \, g \, mL^{-1} = 0.525 \, g \, L^{-1}$.Molar mass of $HCOOH = 46 \, g \, mol^{-1}$.Molality $(m) = \frac{0.525 \, g}{46 \, g \, mol^{-1} \times 1 \, kg} \approx 0.01141 \, mol \, kg^{-1}$.Using the formula $\Delta T_{f} = i K_{f} m$,we have $i = \frac{\Delta T_{f}}{K_{f} m}$.$i = \frac{0.0405}{1.86 \times 0.01141} \approx \frac{0.0405}{0.02122} \approx 1.908$.Thus,the Van't Hoff factor is nearly $1.9$.

Class 12 Chemistry Solutions Abnormal molecular mass

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The depression in freezing point observed for a formic acid solution of concentration $0.5 \, mL \, L^{-1}$ is $0.0405^{\circ} \, C$. The density of formic acid is $1.05 \, g \, mL^{-1}$. The Van't Hoff factor of the formic acid solution is nearly: (Given for water $K_{f} = 1.86 \, K \, kg \, mol^{-1}$)

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A
$0.8$
B
$1.1$
C
$1.9$
D
$2.4$

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When $1.5 \ g$ of phenol $(C_6H_5OH)$ is dissolved in $100 \ g$ of toluene,a decrease in freezing point of $0.56 \ K$ is observed. If the association is dimeric in nature,find the percentage of association. Given: $K_f = 4 \ K \ kg \ mol^{-1}$.

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When $20 \ g$ of naphthoic acid $(C_{11}H_8O_2)$ is dissolved in $50 \ g$ of benzene, a freezing point depression of $2 \ K$ is observed. The van't Hoff factor $(i)$ is [$K_f = 1.72 \ K \ kg \ mol^{-1}$].

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$20 \ g$ of naphthoic acid $(C_{11}H_8O_2)$ dissolved in $50 \ g$ of benzene $(K_f = 1.72 \ K \ kg \ mol^{-1})$ shows a depression in freezing point of $2 \ K$. The Van't Hoff factor is?

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In a solvent,$50\,\%$ of an acid $HA$ dimerizes and the rest dissociates. The van't Hoff factor of the acid is $.....\times 10^{-2}$. (Round off to the nearest integer)

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Solute $A$ associates in water. When $0.7 \ g$ of solute $A$ is dissolved in $42.0 \ g$ of water,it depresses the freezing point by $0.2^{\circ} C$. The percentage association of solute $A$ in water is $..... \ \%$.
[Given: Molar mass of $A = 93 \ g \ mol^{-1}$. Molal depression constant of water is $1.86 \ K \ kg \ mol^{-1}$]

MediumJEE MAIN 2022

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When $1.5 \ g$ of phenol $(C_6H_5OH)$ is dissolved in $100 \ g$ of toluene,a decrease in freezing point of $0.56 \ K$ is observed. If the association is dimeric in nature,find the percentage of association. Given: $K_f = 4 \ K \ kg \ mol^{-1}$.

When $20 \ g$ of naphthoic acid $(C_{11}H_8O_2)$ is dissolved in $50 \ g$ of benzene, a freezing point depression of $2 \ K$ is observed. The van't Hoff factor $(i)$ is [$K_f = 1.72 \ K \ kg \ mol^{-1}$].

$20 \ g$ of naphthoic acid $(C_{11}H_8O_2)$ dissolved in $50 \ g$ of benzene $(K_f = 1.72 \ K \ kg \ mol^{-1})$ shows a depression in freezing point of $2 \ K$. The Van't Hoff factor is?

In a solvent,$50\,\%$ of an acid $HA$ dimerizes and the rest dissociates. The van't Hoff factor of the acid is $.....\times 10^{-2}$. (Round off to the nearest integer)

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