Solutions — JEE Main PYQs

Considering acetic acid dissociates in water, its dissociation constant is $6.25\times 10^{-5}$. If 5 mL of acetic acid is dissolved in 1 litre water, the solution will freeze at $-\mathrm{x}\times 10^{-2}{}^{\circ }\mathrm{C}$, provided pure water freezes at …

Consider the dissociation of the weak acid HX as given below
$\mathrm{HX}(\mathrm{aq})\rightleftharpoons {\mathrm{H}}^{+}(\mathrm{aq})+{\mathrm{X}}^{-}(\mathrm{aq}),\mathrm{Ka}=1.2\times 10^{-5}$
[ ${\mathrm{K}}_{\mathrm{a}}$ : dissociation constant]
The osmotic pressure of 0.03 …

When ' ${\mathrm{x}}^{\prime }\times 10^{-2}\mathrm{mL}$ methanol (molar mass $=32\mathrm{g}$; density $=0.792\mathrm{g}/{\mathrm{cm}}^3$ ) is added to 100 mL water (density $=1\mathrm{g}/{\mathrm{cm}}^3$ ), the following diagram is obtained.

$\mathrm{x}=$ ............ …

Molality of an aqueous solution of urea is 4.44 m. Mole fraction of urea in solution is $x\times 10^{-3}$. Value of $x$ is ____. (integer answer)

A solution containing 10g of an electrolyte ${\mathrm{AB}}_2$ in 100 g of water boils at $100.52^{\circ }\mathrm{C}$. The degree of ionization of the electrolyte ($\alpha$) is ______ $\times 10^{-1}$.
(nearest integer)
[Given : Molar mass of …

$0.05\mathrm{M}{\mathrm{CuSO}}_4$ when treated with $0.01\mathrm{M}{\mathrm{K}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7$ gives green colour solution of ${\mathrm{Cu}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7$. The [SPM : Semi Permeable Membrane]

| …

The vapour pressure of pure benzene and methyl benzene at $27^{\circ }\mathrm{C}$ is given as 80 Torr and 24 Torr, respectively. The mole fraction of methyl benzene in vapour phase, in equilibrium with an equimolar mixture of those two liquids (ideal solution) at the same tempe …

A solution of two miscible liquids showing negative deviation from Raoult's law will have :

Mass of ethylene glycol (antifreeze) to be added to 18.6 kg of water to protect the freezing point at $-24^{\circ }\mathrm{C}$ is ____ kg (Molar mass in ${\mathrm{g}}^{-1}$ for ${}^{-1}$ for ethylene glycol $62,{\mathrm{K}}_{\mathrm{f}}$ of water …

We have three aqueous solutions of NaCl labelled as 'A', 'B' and 'C' with concentration 0.1 M, 0.01 M & 0.001 M, respectively. The value of van t' Hoff factor (i) for these solutions will be in the order.

The quantity which changes with temperature is:

The osmotic pressure of a dilute solution is $7\times 10^5\mathrm{Pa}$ at 273 K. Osmotic pressure of the same solution at 283 K is ____ $\times 10^4{\mathrm{Nm}}^{-2}$.

Identify the mixture that shows positive deviations from Raoult's Law

What happens to freezing point of benzene when small quantity of napthalene is added to benzene?

The solution from the following with highest depression in freezing point/lowest freezing point is

Mass of Urea (${\mathrm{NH}}_2{\mathrm{CONH}}_2$) required to be dissolved in 1000 g of water to reduce the vapour pressure of water by $25\%$ is......g. (Nearest integer)

Given: Molar mass of N, C, O and H are 14, 12, 16 and 1 g ${\mathrm{mol}}^{-1}$ respectively.

Consider the following pairs of solution which will be isotonic at the same temperature. The number of pairs of solutions is/are _____
A. 1 M aq. NaCl and 2 M aq. Urea
B. 1 M aq. ${\mathrm{CaCl}}_2$ and 1.5 M aq. KCl
C. 1.5 M aq. ${\mathrm{AlCl}}_3$ and 2 M aq. …

If the boiling points of two solvents X and Y (having same molecular weights) are in the ratio 2 : 1 and their enthalpy of vaporizations are in the ratio $1:2$, then the boiling point elevation constant of X is $\underline{\mathrm{m}}$ times the boiling point elevation constant …

An aqueous solution of volume $300{\mathrm{cm}}^3$ contains 0.63 g of protein. The osmotic pressure of the solution at 300 K is 1.29 mbar. The molar mass of the protein is ______ $\mathrm{g}{\mathrm{mol}}^{-1}$

Given: $\mathrm{R}=0.083\mathrm{L}$ bar …

The vapour pressure vs. temperature curve for a solution solvent system is shown below.

The boiling point of the solvent is ______ °C

If the degree of dissociation of an aqueous solution of a weak monobasic acid is determined to be 0.3, then the observed depression in freezing point will be _____ % higher than the expected / theoretical depression in freezing point. (Nearest integer)

$0.004$ M $\mathrm{K}{}_2\mathrm{SO}{}_4$ solution is isotonic with $0.01$ M glucose solution. Percentage dissociation of $\mathrm{K}{}_2\mathrm{SO}{}_4$ is $\_\_\_\_$ (Nearest integer)

What weight of glucose must be dissolved in 100 g of water to lower the vapour pressure by 0.20 mm Hg ?
(Assume dilute solution is being formed)
Given : Vapour pressure of pure water is 54.2 mm Hg at room temperature. Molar mass of glucose is …

80 mole percent of ${\mathrm{MgCl}}_2$ is dissociated in aqueous solution. The vapour pressure of 1.0 molal aqueous solution of ${\mathrm{MgCl}}_2$ at $38^{\circ }\mathrm{C}$ is
$\_\_\_\_$ mm Hg. (Nearest integer)

Given : Vapour pressure of water at $38^{\circ }\mathrm{C}$ is 50 …

Solution of 12 g of non - electrolyte (A) prepared by dissolving it in 1000 mL of water exerts the same osmotic pressure as that of 0.05 M glucose solution at the same temperature. The empirical formula of A is ${\mathrm{CH}}_2\mathrm{O}$. The molecular mass of A is ______ g. (N …

Sea water contains $29.25\%\mathrm{NaCl}$ and $19\%{\mathrm{MgCl}}_2$ by weight of solution. The normal boiling point of the sea water is ____ ${}^{\circ }\mathrm{C}$ (Nearest integer)

Assume $100\%$ ionization for both NaCl and ${\mathrm{MgCl}}_2$
Given: …

The vapour pressure of $30\%(\mathrm{w}/\mathrm{v})$ aqueous solution of glucose is ____ mm Hg at $25^{\circ }\mathrm{C}$.
[Given : The density of $30\%(\mathrm{w}/\mathrm{v})$, aqueous solution of glucose is $1.2\mathrm{g}{\mathrm{cm}}^{-3}$ and vapour pressure of pu …

25 mL of an aqueous solution of KCl was found to require 20 mL of $1\mathrm{M}{\mathrm{AgNO}}_3$ solution when titrated using ${\mathrm{K}}_2{\mathrm{CrO}}_4$ as an indicator. What is the depression in freezing point of KCl solution of the given concentration? ____ (Neares …

In the depression of freezing point experiment
A. Vapour pressure of the solution is less than that of pure solvent
B. Vapour pressure of the solution is more than that of pure solvent
C. Only solute molecules solidify at the freezing point
D. Only solvent molecules solidify at t …

The Total pressure observed by mixing two liquid A and B is 350 mm Hg when their mole fractions are 0.7 and 0.3 respectively.
The Total pressure becomes 410 mm Hg if the mole fractions are changed to 0.2 and 0.8 respectively for A and B. The vapour pressure of pure A is ____ mm H …

The number of pairs of the solution having the same value of the osmotic pressure from the following is ____.
(Assume 100% ionization)

A. $0.500\mathrm{M}$ ${\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH}(\mathrm{aq})$ and $0.25\mathrm{M}$ $\mathrm{KBr}(\mathrm{aq})$
B. …

Solid Lead nitrate is dissolved in 1 litre of water. The solution was found to boil at $100.15^{\circ }\mathrm{C}$. When 0.2 mol of NaCl is added to the resulting solution, it was observed that the solution froze at $-0.8^{\circ }\mathrm{C}$. The solutbility product of …

A solution containing 2 g of a non-volatile solute in 20 g of water boils at 373.52 K. The molecular mass of the solute is ______ $\mathrm{g}{\mathrm{mol}}^{-1}$. (Nearest integer)

Given, water boils at $373\mathrm{K},{\mathrm{K}}_{\mathrm{b}}$ for water …

20% of acetic acid is dissociated when its 5 g is added to 500 mL of water. The depression in freezing point of such water is ______ $\times 10^{-3}$ ${}^{\circ }\mathrm{C}$. Atomic mass of C, H and O are 12, 1 and 16 a.m.u. respectively.
[Given: Molal depression constant and densit …

Evaluate the following statements for their correctness.
(A) The elevation in boiling point temperature of water will be same for 0.1 M NaCl and 0.1 M urea.
(B) Azeotropic mixtures boil without change in their composition
(C) Osmosis always takes place from hypertonic to hypotoni …

Lead storage battery contains $38\%$ by weight solution of ${\mathrm{H}}_2{\mathrm{SO}}_4$. The van't Hoff factor is 2.67 at this concentration. The temperature in Kelvin at which the solution in the battery will freeze is ____ (Nearest integer).
Given …

At $27^{\circ }\mathrm{C}$, a solution containing 2.5 g of solute in 250.0 mL of solution exerts an osmotic pressure of 400 Pa. The molar mass of the solute is ______ g ${\mathrm{mol}}^{-1}$ (Nearest integer)

(Given: $\mathrm{R}=0.083\mathrm{L}$ bar …

1.80 g of solute A was dissolved in $62.5{\mathrm{cm}}^3$ of ethanol and freezing point of the solution was found to be 155.1 K. The molar mass of solute A is ______ $\mathrm{g}{\mathrm{mol}}^{-1}$.
[Given: Freezing point of ethanol is 156.0 K.
Density of ethanol is …

150 g of acetic acid was contaminated with 10.2 g ascorbic acid $\left({\mathrm{C}}_6{\mathrm{H}}_8{\mathrm{O}}_6\right)$ to lower down its freezing point by ${\left(\mathrm{x}\times 10^{-1}\right)}^{\circ }\mathrm{C}$. The value of x is ______.
(Nearest integer)
[Given …

A gaseous mixture of two substances A and B, under a total pressure of 0.8 atm is in equilibrium with an ideal liquid solution. The mole fraction of substance A is 0.5 in the vapour phase and 0.2 in the liquid phase. The vapour pressure of pure liquid A is _____ atm. (Nearest int …

Boiling point of a $2\%$ aqueous solution of a nonvolatile solute A is equal to the boiling point of $8\%$ aqueous solution of a non-volatile solute B . The relation between molecular weights of A and B is.

The depression in freezing point observed for a formic acid solution of concentration $0.5\mathrm{mL}{\mathrm{L}}^{-1}$ is $0.0405^{\circ }\mathrm{C}$. Density of formic acid is $1.05\mathrm{g}{\mathrm{mL}}^{-1}$. The Van't Hoff factor of the formic acid solution is nea …

The elevation in boiling point for 1 molal solution of non-volatile solute A is 3 K . The depression in freezing point for 2 molal solution of A in the same solvent is 6 K . The ratio of ${\mathrm{K}}_{\mathrm{b}}$ and ${\mathrm{K}}_{\mathrm{f}}$ i.e., …

When a certain amount of solid A is dissolved in 100 g of water at $25^{\circ }\mathrm{C}$ to make a dilute solution, the vapour pressure of the solution is reduced to one-half of that of pure water. The vapour pressure of pure water is 23.76 mmHg. The number of moles of solute A …

Two solutions A and B are prepared by dissolving 1 g of non-volatile solutes X and Y . respectively in 1 kg of water. The ratio of depression in freezing points for A and B is found to be $1:4$. The ratio of molar masses of X and Y is :

2.5 g of protein containing only glycine $\left({\mathrm{C}}_2{\mathrm{H}}_5{\mathrm{NO}}_2\right)$ is dissolved in water to make 500 mL of solution. The osmotic pressure of this solution at 300 K is found to be $5.03\times 10^{-3}$ bar. The total number of glycine units prese …

A solution containing $2.5\times 10^{-3}\mathrm{kg}$ of a solute dissolved in $75\times 10^{-3}\mathrm{kg}$ of water boils at 373.535 K. The molar mass of the solute is ______ ${\mathrm{g}\mathrm{mol}}^{-1}$. [nearest integer]
(Given: …

The vapour pressures of two volatile liquids A and B at $25^{\circ }\mathrm{C}$ are 50 Torr and 100 Torr, respectively. If the liquid mixture contains 0.3 mole fraction of A, then the mole fraction of liquid B in the vapour phase is $\frac{x}{17}$. The value of $x$ is ______.

Elevation in boiling point for 1.5 molal solution of glucose in water is 4 K . The depression in freezing point for 4.5 molal solution of glucose in water is 4 K . The ratio of molal elevation constant to molal depression constant …

The osmotic pressure exerted by a solution prepared by dissolving 2.0 g of protein of molar mass $60\mathrm{kg}{\mathrm{mol}}^{-1}$ in 200 mL of water at $27^{\circ }\mathrm{C}$ is $\_\_\_\_$ Pa. [integer value]
(use $\mathrm{R}=0.083\mathrm{L}$ bar …