In a solution with molality m,if the solute e | vedclass

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

Question

(D) The elevation in boiling point is given by $\Delta T_b = i 	imes K_b 	imes m$. For a solute that dimerizes,the van't Hoff factor $i$ is given by

Vedclass · Accepted Answer

$mK_b / 3$

Vedclass · Answer

(D) The elevation in boiling point is given by $\Delta T_b = i 	imes K_b 	imes m$. For a solute that dimerizes,the van't Hoff factor $i$ is given by $i = 1 - \alpha + \alpha / 2 = 1 - \alpha / 2$,where $\alpha$ is the degree of association. Since $0 \le \alpha \le 1$,the range for $i$ is $1 - 1/2 \le i \le 1 - 0$,which means $0.5 \le i \le 1$. Therefore,the range for $\Delta T_b$ is $0.5 mK_b \le \Delta T_b \le 1 mK_b$. Checking the options: $A) 0.5 mK_b$ (Possible at $\alpha = 1$) $B) 0.6 mK_b$ (Possible at $\alpha = 0.8$) $C) 0.75 mK_b$ (Possible at $\alpha = 0.5$) $D) 0.33 mK_b$ (Not possible as $i < 0.5$ is required,which is outside the range).

In a solution with molality $m$,if the solute exists in the form of a dimer,which of the following cannot be the elevation in the boiling point of the solution?

Similar Questions

The observed and calculated molecular weights of calcium nitrate are $65.6$ and $164$ respectively. The degree of dissociation of calcium nitrate is .......... $\%$.

$20 \ g$ 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)

$0.2$ molal aqueous solution of $KCl$ freezes at $-0.680^{\circ} C$. Calculate van't Hoff factor for this solution. $(K_{f} = 1.86 \ K \ kg \ mol^{-1})$

Pure benzene freezes at $5.3\,^oC$. $A$ solution of $0.223\, g$ of phenylacetic acid $(C_6H_5CH_2COOH)$ in $4.4\, g$ of benzene $(K_f = 5.12\, K\, kg\, mol^{-1})$ freezes at $4.47\,^oC$. From this,it can be concluded that phenylacetic acid ........

Vedclass Test Series

Exam Paper Generator

Online Exam Module