Solutions · Chemistry · JEE Advanced
Numerical
1
Vessel-1 contains $\mathbf{w}_2 \mathrm{~g}$ of a non-volatile solute $\mathbf{X}$ dissolved in $\mathbf{w}_1 \mathrm{~g}$ of water. Vessel- 2 contains $\mathbf{w}_2 \mathrm{~g}$ of another non-volatile solute $\mathbf{Y}$ dissolved in $\mathbf{w}_1 \mathrm{~g}$ of water. Both the vessels are at the same temperature and pressure. The molar mass of $\mathbf{X}$ is $80 \%$ of that of $\mathbf{Y}$. The van't Hoff factor for $\mathbf{X}$ is 1.2 times of that of $\mathbf{Y}$ for their respective concentrations.
The elevation of boiling point for solution in Vessel-1 is ________ $\%$ of the solution in Vessel-2.
The elevation of boiling point for solution in Vessel-1 is ________ $\%$ of the solution in Vessel-2.
JEE Advanced 2024 Paper 2 Online
2
$50 \mathrm{~mL}$ of 0.2 molal urea solution (density $=1.012 \mathrm{~g} \mathrm{~mL}^{-1}$ at $300 \mathrm{~K}$ ) is mixed with $250 \mathrm{~mL}$ of a solution containing $0.06 \mathrm{~g}$ of urea. Both the solutions were prepared in the same solvent. The osmotic pressure (in Torr) of the resulting solution at $300 \mathrm{~K}$ is _______.
[Use: Molar mass of urea $=60 \mathrm{~g} \mathrm{~mol}^{-1}$; gas constant, $\mathrm{R}=62$ L Torr $\mathrm{K}^{-1} \mathrm{~mol}^{-1}$;
Assume, $\Delta_{\text {mix }} \mathrm{H}=0, \Delta_{\text {mix }} \mathrm{V}=0$ ]
[Use: Molar mass of urea $=60 \mathrm{~g} \mathrm{~mol}^{-1}$; gas constant, $\mathrm{R}=62$ L Torr $\mathrm{K}^{-1} \mathrm{~mol}^{-1}$;
Assume, $\Delta_{\text {mix }} \mathrm{H}=0, \Delta_{\text {mix }} \mathrm{V}=0$ ]
JEE Advanced 2023 Paper 2 Online
3
An aqueous solution is prepared by dissolving $0.1 \mathrm{~mol}$ of an ionic salt in $1.8 \mathrm{~kg}$ of water at $35^{\circ} \mathrm{C}$. The salt remains $90 \%$ dissociated in the solution. The vapour pressure of the solution is $59.724 \mathrm{~mm}$ of Hg. Vapor pressure of water at $35{ }^{\circ} \mathrm{C}$ is $60.000 \mathrm{~mm}$ of $\mathrm{Hg}$. The number of ions present per formula unit of the ionic salt is _________.
JEE Advanced 2022 Paper 2 Online
4
The value of x is ________.
JEE Advanced 2021 Paper 1 Online
5
The value of | y | is ________.
JEE Advanced 2021 Paper 1 Online
6
Liquids A and B form ideal solution for all compositions of A and B at 25$$^\circ $$C. Two such solutions with 0.25 and 0.50 mole fractions of A have the total vapour pressure of 0.3 and 0.4 bar, respectively. What is the vapour pressure of pure liquid B in bar?
JEE Advanced 2020 Paper 2 Offline
7
On dissolving 0.5 g of a non-volatile non-ionic solute to 39 g of benzene, its vapor pressure decreases from 650 mmHg to 640 mmHg. The depression of freezing point of benzene (in K) upon addition of the solute is .............
(Given data: Molar mass and the molal freezing point depression constant of benzene are 78 g mol-1 and 5.12 K kg mol-1, respectively).
(Given data: Molar mass and the molal freezing point depression constant of benzene are 78 g mol-1 and 5.12 K kg mol-1, respectively).
JEE Advanced 2019 Paper 1 Offline
8
The plot given below shows $$P-T$$ curves (where $$P$$ is the pressure and $$T$$ is the temperature) for two solvents $$X$$ and $$Y$$ and isomolal solutions of $$NaCl$$ in these solvents. $$NaCl$$ completely dissociates in both the solvents.
On addition of equal number of moles of a non-volatile solute $$S$$ in equal amount (in $$kg$$) of these solvents, the elevation of boiling point of solvent $$X$$ is three times that of solvent $$Y$$. Solute $$S$$ is known to undergo dimerization in these solvents. If the degree of dimerization is $$0.7$$ in solvent $$Y$$, the degree of dimerization in solvent $$X$$ is ___________.
On addition of equal number of moles of a non-volatile solute $$S$$ in equal amount (in $$kg$$) of these solvents, the elevation of boiling point of solvent $$X$$ is three times that of solvent $$Y$$. Solute $$S$$ is known to undergo dimerization in these solvents. If the degree of dimerization is $$0.7$$ in solvent $$Y$$, the degree of dimerization in solvent $$X$$ is ___________.
JEE Advanced 2018 Paper 1 Offline
9
Liquids A and B form ideal solution over the entire range of composition. At temperature $$T,$$ equimolar binary solution of liquids $$A$$ and $$B$$ has vapor pressure $$45$$ $$Torr.$$ At the same temperature, a new solution of $$A$$ and $$B$$ having mole fractions $${X_A}$$ and $${X_B}$$, respectively, has vapour pressure of $$22.5$$ $$Torr.$$ The value of $${x_A}/{x_B}$$ in the new solution is ___________.
(given that the vapor pressure of pure liquid $$A$$ is $$20$$ $$Torr$$ at temperature $$T$$)
(given that the vapor pressure of pure liquid $$A$$ is $$20$$ $$Torr$$ at temperature $$T$$)
JEE Advanced 2018 Paper 1 Offline
10
The mole fraction of a solute in a solution is 0.1. At 298 K, molarity of this solution is the same as its
molality. Density of this solution at 298 K is 2.0 g cm–3 . The ratio of the molecular weights of the solute and solvent, $$\left( {{{M{W_{solute}}} \over {M{W_{solvent}}}}} \right)$$, is
JEE Advanced 2016 Paper 1 Offline
11
If the freezing point of a 0.01 molal aqueous solution of a cobalt (III) chloride-ammonia complex(which
behaves as a strong electrolyte) is – 0.0558oC, the number of chloride(s) in the coordination sphere of the
complex is [Kf of water = 1.86 K kg mol–1 ]
JEE Advanced 2015 Paper 1 Offline
12
MX2 dissociates in M2+ and X- ions in an aqueous solution, with a degree of dissociation ($$\alpha$$) of 0.5. The
ratio of the observed depression of freezing point of the aqueous solution to the value of the depression of
freezing point in the absence of ionic dissociation is
JEE Advanced 2014 Paper 1 Offline
13
75.2 g of C6H5OH (phenol) is dissolved in a solvent of Kf = 14. If the depression in freezing point is 7 K then find the % of phenol that dimerises.
IIT-JEE 2006
MCQ (Single Correct Answer)
1
Pure water freezes at $$273$$ $$K$$ and $$1$$ bar. The addition of $$34.5$$ $$g$$ of ethanol to $$500$$ $$g$$ of water changes the freezing point of the solution. Use the freezing point depression constant of water as $$2$$ kg $$mo{l^{ - 1}}.$$ The figures shown below represent plots of vapor pressure $$(V.P.)$$ versus temperature $$(T).$$ [molecular weight of ethanol is $$46$$ $$g$$ $$mo{l^{ - 1}}.$$ ] Among the following, the option representing change in the freezing point is
JEE Advanced 2017 Paper 2 Offline
2
The qualitative sketches I, II and III given below show the variation of surface tension with molar concentration of three different aqueous solutions of KCl, CH3OH and CH3(CH2)11 OSO$$_3^ - $$ Na+ at room temperature. The correct assignment of the sketches is
JEE Advanced 2016 Paper 2 Offline
3
For a dilute solution containing 2.5 g of a non-volatile non-electrolyte solute in 100 g of water. the elevation in boiling point at 1 atm pressure is 2oC. Assuming concentration of solute is much lower than the concentration of solvent, the vapour pressure (mm of Hg) of the solution is (take Kb = 0.76 K Kg mol-1)
IIT-JEE 2012 Paper 2 Offline
4
The freezing point (in oC) of a solution containing 0.1 g of K3[Fe(CN)6] (Mol. wt. 329) in 100 g of water (Kf = 1.86 K kg mol-1) is
IIT-JEE 2011 Paper 2 Offline
5
The Henry's law constant for the solubility of N$$_2$$ gas in water at 298 K is 1.0 $$\times$$ 10$$^5$$ atm. The mole fraction of N$$_2$$ in air is 0.8. The number of moles of N$$_2$$ from air dissolved in 10 moles of water at 298 K and 5 atm pressure is
IIT-JEE 2009 Paper 1 Offline
6
The freezing point of the solution M is :
IIT-JEE 2008 Paper 1 Offline
7
The vapour pressure of the solution M is :
IIT-JEE 2008 Paper 1 Offline
8
Water is added to the solution M such that the fraction of water in the solution becomes 0.9 mole. The boiling point of this solution is:
IIT-JEE 2008 Paper 1 Offline
9
The elevation in boiling point of a solution of 13.44 g of CuCl2 in 1kg of water using the following information will be (Molecular weight of CuCl2 = 134.4 and Kb = 0.52 K molal-1)
IIT-JEE 2005 Screening
10
The freezing point of equimolal aqueous solutions will be highest for
IIT-JEE 1990
MCQ (More than One Correct Answer)
1
For a solution formed by mixing liquids $$L$$ and $$M,$$ the vapor pressure of $$L$$ plotted against the mole fraction of $$M$$ in solution is shown in the following figure. Here $${X_L}$$ and $${X_M}$$ represent mole fractions of $$L$$ and $$M,$$ respectively, in the solution. The correct statement(s) applicable to this system is (are)
JEE Advanced 2017 Paper 1 Offline
2
Mixture (s) showing positive deviation from Raoult’s law at 35oC is (are)
JEE Advanced 2016 Paper 2 Offline
Subjective
1
1.22 g of benzoic acid is dissolved in 100 g of acetone and 100 g of benzene separately. Boiling point of the solution in acetone increases by 0.17 oC, while that in the benzene increases by 0.13oC; Kb for acetone and benzene is 1.7 K kg mol-1 and 2.6 K kg mol-1. Find molecular weight of the benzoic acid in two cases and justify your answer.
IIT-JEE 2004
2
To 500 cm3 of water, 3.0 $$\times$$ 10-3 kg of acetic acid is added. If 23% of acetic acid is dissociated, what will be the depression in freezing point? Kf and density of water are 1.86 K kg-1 mol-1 and 0.997 g cm-3, respectively
IIT-JEE 2000
3
Nitrobenzene is formed as the major product along with a minor product in the reaction of benzene with a hot mixture of nitric acid and sulphuric acid. The minor product consists of carbon : 42.86 %, hydrogen : 2.40%, nitrogen : 16.67% and oxygen : 38.07% (i) Calculate the empirical formula of the minor product. (ii) When 5.5 g of the minor product is dissolved in 45 g of benzene, the boiling point of the solution is 1.84 oC higher than that of pure benzene. Calculate the molar mass of the minor product and determine its molecular and structural formula. (Molal boiling point elevation constant of benzene is 2.53 K kg mol-1)
IIT-JEE 1999
4
A solution of a nonvolatile solute in water freezes at -0.30oC. The vapour pressure of pure water at 298 K s 23.51 mm Hg and Kf for water is 1.86 K kg mol-1. Calculate the vapour pressure of this solution at 298 K.
IIT-JEE 1998
5
The molar volume of liquid benzene (density = 0.877 g mL-1) increases by a factor of 2750 as it vaporises at 20oC and that of liquid toluene (density = 0.867 g mL-1) increases by a factor of 7720 at 20oC. A solution of benzene and toluene at 20oC has vapour pressure of 46.0 Torr. Find the mole fraction of benzene in the vapour above the solution.
IIT-JEE 1996
6
What weight of the non-volatile solute, urea(NH2 - CO - NH2) needs to be dissolved in 100g of water, in order to decrease the vapour pressure of water by 25%? What will be the molality of the solution?
IIT-JEE 1993
7
The degree of dissociation of calcium nitrate in a dilute aqueous solution, containing 7.0 g. of the salt per 100 gm of water at 100oC is 70%. If the vapour pressure of water at 100oC is 760 mm, calculate the vapour pressure of the solution.
IIT-JEE 1991
8
The vapour pressure of pure benzene at a certain temperature is 640 mm Hg. A non-volatile non-electrolyte solid weighing 2.175 g is added to 39.0 g of benzene. The vapour pressure of the solution is 600 mm Hg. What is the molecular weight of the solid substance?
IIT-JEE 1990
9
The vapour pressure of a dilute aqueous solution of glucose (C6H12O6) is 750 mm of mercury at 373 K. Calculate (i) molality, and (ii) mole fraction of the solution.
IIT-JEE 1989
10
The vapour pressure of ethanol and methanol are 44.5 and 88.7 mm Hg respectively. An ideal solution is formed at the same temperature by mixing 60 g of ethanol with 40 g of methanol. Calculate the total vapour pressure of the solution and the mole fraction of methanol in the vapour.
IIT-JEE 1986
11
An organic compound CxH2yOy was burnt with twice the amount of oxygen needed for complete combustion of CO2 and H2O. The hot gases when cooled to 0oC and 1 atm pressure, measured 2.24 litres. The water collected during cooling weighed 0.9 g. The vapour pressure of pure water at 20oC is 17.5 mm Hg and is lowered by 0.104 mm when 50 g of the organic compound are dissolved in 1000 g of water. Give the molecular formula of the organic compound.
IIT-JEE 1983
12
The vapour pressure of pure benzene is 639.7 mm of mercury and the vapour of a solution of a solute in benzene at the same temperature is 631.9 mm of mercury. Calculate this molality of the solution.
IIT-JEE 1981