(C) Given: Degree of association $\alpha = 80\% = 0.8$ and $n = 4$ (for tetramerization). Van't Hoff factor $i = 1 + (\frac{1}{n} - 1)\alpha = 1 + (\f

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

(C) Given: Degree of association $\alpha = 80\% = 0.8$ and $n = 4$ (for tetramerization). Van't Hoff factor $i = 1 + (\frac{1}{n} - 1)\alpha = 1 + (\frac{1}{4} - 1) \times 0.8 = 1 - 0.6 = 0.4$. Depression in freezing point $\Delta T_f = i \times K_f \times m$. $0.3 = 0.4 \times 1.86 \times \frac{2.5 \times 1000}{M_A \times 100}$. $0.3 = 0.4 \times 1.86 \times \frac{25}{M_A}$. $M_A = \frac{0.4 \times 1.86 \times 25}{0.3} = \frac{18.6}{0.3} = 62 \text{ g mol}^{-1}$.

Class 12 Chemistry Solutions Abnormal molecular mass

Medium

$A$ non-volatile solute '$A$' tetramerizes in water to the extent of $80\%$. $2.5 \text{ g}$ of '$A$' in $100 \text{ g}$ of water lowers the freezing point by $0.3^\circ \text{C}$. The molar mass of $A$ in $\text{g mol}^{-1}$ is ($K_f$ for water $= 1.86 \text{ K kg mol}^{-1}$)

KCET 2019 All KCET

A
$155$
B
$354$
C
$62$
D
$221$

Explore More

Browse All

Question Bank

All Subjects

Class 12 Questions

Class 12

Chemistry Questions

Chapter

Solutions

Subtopic

Abnormal molecular mass

Previous Year

KCET 2019 Paper All KCET years →

$A$ $0.004 \ M$ solution of $Na_2SO_4$ is isotonic with a $0.010 \ M$ solution of glucose at the same temperature. The apparent degree of dissociation of $Na_2SO_4$ is $..... \ \%$.

DifficultIIT 2004

View Solution

In an experiment to estimate the molecular weight of benzoic acid by the elevation in boiling point method,the experimental value of the molecular weight was double the actual value. Calculate the degree of association of the dimer.

MediumTS EAMCET 2018

View Solution

For an $AB$ type ionic substance,which ratio of theoretical to experimental molecular mass is not consistent?

Easy

View Solution

The experimental depression in freezing point of a dilute solution is $0.025 \ K$. If the van't Hoff factor $(i)$ is $2.0$,the calculated depression in freezing point (in $K$) is

MediumTS EAMCET 2016

View Solution

Benzoic acid has a higher molecular weight in benzene and a lower molecular weight in water because:

Difficult

View Solution

Vedclass Products

For Students

Vedclass Test Series

Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.

Start Free Trial

For Teachers

Exam Paper Generator

Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.

Try Free

For Institutes

Online Exam Module

Live online exams with unlimited students, 360° analytics & white-label branding.

See Demo

$A$ non-volatile solute '$A$' tetramerizes in water to the extent of $80\%$. $2.5 \text{ g}$ of '$A$' in $100 \text{ g}$ of water lowers the freezing point by $0.3^\circ \text{C}$. The molar mass of $A$ in $\text{g mol}^{-1}$ is ($K_f$ for water $= 1.86 \text{ K kg mol}^{-1}$)

Similar Questions

$A$ $0.004 \ M$ solution of $Na_2SO_4$ is isotonic with a $0.010 \ M$ solution of glucose at the same temperature. The apparent degree of dissociation of $Na_2SO_4$ is $..... \ \%$.

In an experiment to estimate the molecular weight of benzoic acid by the elevation in boiling point method,the experimental value of the molecular weight was double the actual value. Calculate the degree of association of the dimer.

For an $AB$ type ionic substance,which ratio of theoretical to experimental molecular mass is not consistent?

The experimental depression in freezing point of a dilute solution is $0.025 \ K$. If the van't Hoff factor $(i)$ is $2.0$,the calculated depression in freezing point (in $K$) is

Benzoic acid has a higher molecular weight in benzene and a lower molecular weight in water because:

Vedclass Test Series

Exam Paper Generator

Online Exam Module