(A) The relative lowering of vapour pressure is given by $\frac{P^o - P}{P^o} = \chi_{solute} = \frac{n}{n + N}$.Since the amount of solvent (water) i

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Same as that of $2^{nd}$ solution

(A) The relative lowering of vapour pressure is given by $\frac{P^o - P}{P^o} = \chi_{solute} = \frac{n}{n + N}$.Since the amount of solvent (water) is the same $(1 \ L)$ and the amount of solute is small,the mole fraction is directly proportional to the number of moles of solute $(n)$.For the first solution,moles of urea $= \frac{12 \ g}{60 \ g/mol} = 0.2 \ mol$.For the second solution,moles of cane sugar $= \frac{68.4 \ g}{342 \ g/mol} = 0.2 \ mol$.Since the number of moles of solute is the same in both solutions,the lowering of vapour pressure will be the same.

Class 12 Chemistry Solutions Lowering of vapour pressure

Medium

$A$ solution is obtained by dissolving $12 \ g$ of urea (mol.wt. $60$) in a litre of water. Another solution is obtained by dissolving $68.4 \ g$ of cane sugar (mol.wt. $342$) in a litre of water at the same temperature. The lowering of vapour pressure in the first solution is

A
Same as that of $2^{nd}$ solution
B
Nearly one-fifth of the $2^{nd}$ solution
C
Double that of $2^{nd}$ solution
D
Nearly five times that of $2^{nd}$ solution

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Lowering of vapour pressure

When a non-volatile solute is added to the solvent,the vapour pressure of the solvent decreases by $10 \ mm \ Hg$. The mole fraction of the solute in the solution is $0.2$. What would be the mole fraction of the solvent if the decrease in vapour pressure is $20 \ mm \ Hg$?

MediumJEE MAIN 2025

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At $300 \ K$,the vapour pressures of two pure liquids,$A$ and $B$ are $100 \ mm \ Hg$ and $500 \ mm \ Hg$,respectively. If in a mixture of $A$ and $B$,the total vapour pressure is $300 \ mm \ Hg$,the mole fractions of $A$ in the liquid and in the vapour phase,respectively,are:

MediumKVPY 2011

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Two different solutions were prepared by dissolving different quantities of glucose in the same quantity of water. For the given graph,which statement is incorrect?

Medium

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$9 \ g$ anhydrous oxalic acid (mol. $Wt. = 90$) was dissolved in $9.9 \ moles$ of water. If vapour pressure of pure water is $P_1^o$,the vapour pressure of solution is (in $P_1^o$)

DifficultMHT CET 2019

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At $25^\circ C$,the vapor pressure of $CCl_4$ is $143 \ mm \ Hg$. If $0.5 \ g$ of a non-volatile solute (molar mass $= 65 \ g/mol$) is dissolved in $100 \ mL$ of $CCl_4$,the vapor pressure of the resulting solution is $...... \ mm \ Hg$. (Density of $CCl_4 = 1.58 \ g/cm^3$)

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$A$ solution is obtained by dissolving $12 \ g$ of urea (mol.wt. $60$) in a litre of water. Another solution is obtained by dissolving $68.4 \ g$ of cane sugar (mol.wt. $342$) in a litre of water at the same temperature. The lowering of vapour pressure in the first solution is

Similar Questions

When a non-volatile solute is added to the solvent,the vapour pressure of the solvent decreases by $10 \ mm \ Hg$. The mole fraction of the solute in the solution is $0.2$. What would be the mole fraction of the solvent if the decrease in vapour pressure is $20 \ mm \ Hg$?

At $300 \ K$,the vapour pressures of two pure liquids,$A$ and $B$ are $100 \ mm \ Hg$ and $500 \ mm \ Hg$,respectively. If in a mixture of $A$ and $B$,the total vapour pressure is $300 \ mm \ Hg$,the mole fractions of $A$ in the liquid and in the vapour phase,respectively,are:

Two different solutions were prepared by dissolving different quantities of glucose in the same quantity of water. For the given graph,which statement is incorrect?

$9 \ g$ anhydrous oxalic acid (mol. $Wt. = 90$) was dissolved in $9.9 \ moles$ of water. If vapour pressure of pure water is $P_1^o$,the vapour pressure of solution is (in $P_1^o$)

At $25^\circ C$,the vapor pressure of $CCl_4$ is $143 \ mm \ Hg$. If $0.5 \ g$ of a non-volatile solute (molar mass $= 65 \ g/mol$) is dissolved in $100 \ mL$ of $CCl_4$,the vapor pressure of the resulting solution is $...... \ mm \ Hg$. (Density of $CCl_4 = 1.58 \ g/cm^3$)

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