JEEChemistry

Solutions

128 JEE Chemistry previous year questions on Solutions — options free on every question; 13 include the answer & explanation free, the rest unlock with PYQ Pass.

Q1 FREE PREVIEW
PYQ
For a dilute solution, Raoult's law states that
athe lowering of vapour pressure is equal to the mole fraction of solute
bthe relative lowering of vapour pressure is equal to the mole fraction of solute
cthe relative lowering of vapour pressure is proportional to the amount of solute in solution
dthe vapour pressure of the solution is equal to the mole fraction of solvent
✓ Correct answer: b) the relative lowering of vapour pressure is equal to the mole fraction of solute
ExplanationFor a dilute solution, Raoult's law states that the relative lowering of vapour pressure is equal to the mole fraction of solute.
Q2 FREE PREVIEW
PYQ
During depression of freezing point in a solution the following are in equilibrium
aliquid solvent, solid solvent
bliquid solvent, solid solute
cliquid solute, solid solute
dliquid solute, solid solvent
✓ Correct answer: a) liquid solvent, solid solvent
ExplanationDuring depression of freezing point, the equilibrium is established between: liquid solvent ⇌ solid solvent Hence, the correct answer is: Option A — liquid solvent, solid solvent Explanation: Freezing point is the temperature at which a solvent changes from liquid to solid.When a non-volatile solute is added, the equilibrium between liquid solvent and solid solvent shifts, causing a lowering of freezing point.
Q3 FREE PREVIEW
PYQ
Identify the mixture that shows positive deviations from Raoult's Law
aCHCl3 + (CH3)2CO
b(CH3)2CO + C6H5NH2
c(CH3)2CO + CS2
dCHCl3 + C6H6
✓ Correct answer: c) (CH3)2CO + CS2
ExplanationMixing polar acetone with non-polar CS₂ weakens intermolecular attractions (A–B < A– A/B–B) → positive deviation from Raoult’s law.The other pairs (acetone–chloroform, acetone– aniline, chloroform–benzene) form specific associations/H-bonding → negative deviation.
Q4 FREE PREVIEW
PYQ

What is the freezing point depression constant of a solvent 50 g of which contain 1 g of non-volatile solute(M.W: 256 g/mol and depression in freezing point is 0.4 K.
Memory Based Question 28/Jan/25 Morning shift

a

\(0.372\mathrm{K}\mathrm{Kg}{\mathrm{mol}}^{-1}\)

b

\(4.213\mathrm{K}\mathrm{Kg}{\mathrm{mol}}^{-1}\)

c

\(1.86\mathrm{K}\mathrm{Kg}{\mathrm{mol}}^{-1}\)

d

\(5.12\mathrm{K}\mathrm{Kg}{\mathrm{mol}}^{-1}\)

✓ Correct answer: d)

\(5.12\mathrm{K}\mathrm{Kg}{\mathrm{mol}}^{-1}\)

Explanation

\(\mathrm{Depression}\mathrm{in}\mathrm{freezing}\mathrm{point}∆{\mathrm{T}}_{\mathrm{b}}={\mathrm{K}}_{\mathrm{f}}.\mathrm{m}\\ \mathrm{molality}\mathrm{m}=\frac{1}{256}\times \frac{1000}{50}=0.0781\\ {\mathrm{K}}_{\mathrm{f}}=\frac{∆{\mathrm{T}}_{\mathrm{b}}}{\mathrm{m}}=0.4/0.0781=5.12\mathrm{KKg}/\mathrm{mol}\)

Q5 FREE PREVIEW
PYQ

Molality \(( m )\) of \(3 M\) aqueous solution of \(NaCl\) is

(Given : Density of solution \(=1.25 ~g mL ^{-1}\), Molar mass in \(g mol ^{-1}\) : \(\mathrm{Na}:23,\mathrm{Cl}:35.5\))

[JEE Main 2024, 6 Apr (Shift 2)]

a

\(2.90 \) m

b

\(2.79\) m

c

\(1.90\) m

d

\(3.85\) m

✓ Correct answer: b)

\(2.79\) m

Explanation

Molality \((m)\) is given as

\(m=\frac{{n}_{\text{solute }}}{k{g}_{\text{solvent }}}\)


To calculate no. of moles of solute we take the help of molarity and to determine mass of solvent we take the help of density of solution. \(3 M\) solution of \(N a C l\) implies that there are 3 moles of \(N a C l\) in every 1 litre of solution. Considering \(1 L\) of solution, we have

\({n}_{\mathrm{NaCl}}=3\mathrm{mol}\)

Mass of \(1 L\) solution of \(\mathrm{NaCl}=(\) volume \()(\) density )

\(\begin{matrix} & =(1000\mathrm{mL})(1.25{\mathrm{gmol}}^{−1}) \\ & =1250\mathrm{g}\end{matrix}\)

Mass of NaCl in 1L of solution \(\begin{matrix} & =({n}_{\mathrm{NaCl}})({\mathrm{mm}}_{\mathrm{NaCl}})\end{matrix}\)

\(\begin{matrix} & =(3\mathrm{mol})(58.5{\mathrm{gmol}}^{−1}) \\ & =175.5\mathrm{g}\end{matrix}\)

Mass of solvent \(\left({\mathrm{H}}_{2}\mathrm{O}\right)=\) Mass of solution - Mass of solute \(=(1250\mathrm{g})-(175.5\mathrm{g})\)

\(=1074.5g\)

Thus

\(\begin{matrix} & m=\frac{{n}_{\text{solute}}}{{g}_{\text{solv}}}\frac{1000g}{kg} \\ & =\frac{3\mathrm{mol}}{1074.5g}\times \frac{1000g}{\mathrm{kg}} \\ & 2.79molk{g}^{-1}\end{matrix}\\\)

Alternatively \(m=\frac{{M}_{\text{soln }}}{1000d−{M}_{\text{soln }m{m}_{\text{solute }}}}\times 1000\)

\(\begin{matrix} & =\frac{3}{(1000)(1.25)−(3)(58.5)}\times 1000 \\ & =2.79{\mathrm{molkg}}^{−1}\end{matrix}\)

Q6 FREE PREVIEW
PYQ

In a 3M aqueous solution of NaCl, having density 1.25 g/ml, what will be the molality of the solution?

a

2.65

b

1.79

c

2.79

d

3

✓ Correct answer: c)

2.79

Explanation

\(molality(m)=\frac{1000M}{1000d-M\times {M}_{0}}(whereM=molarity,{M}_{0}=molarmass)\\ m=\frac{3000}{1250-58.5\times 3}=2.79\)

Q7 FREE PREVIEW
PYQ

What is the freezing point depression constant of a solvent 50 g of which contain 1 g of non-volatile solute(M.W: 256 g/mol and depression in freezing point is 0.4 K.
Memory Based Question 28/Jan/25 Morning shift

a

\(0.372\mathrm{K}\mathrm{Kg}{\mathrm{mol}}^{-1}\)

b

\(4.213\mathrm{K}\mathrm{Kg}{\mathrm{mol}}^{-1}\)

c

\(1.86\mathrm{K}\mathrm{Kg}{\mathrm{mol}}^{-1}\)

d

\(5.12\mathrm{K}\mathrm{Kg}{\mathrm{mol}}^{-1}\)

✓ Correct answer: d)

\(5.12\mathrm{K}\mathrm{Kg}{\mathrm{mol}}^{-1}\)

Explanation

\(\mathrm{Depression}\mathrm{in}\mathrm{freezing}\mathrm{point}∆{\mathrm{T}}_{\mathrm{b}}={\mathrm{K}}_{\mathrm{f}}.\mathrm{m}\\ \mathrm{molality}\mathrm{m}=\frac{1}{256}\times \frac{1000}{50}=0.0781\\ {\mathrm{K}}_{\mathrm{f}}=\frac{∆{\mathrm{T}}_{\mathrm{b}}}{\mathrm{m}}=0.4/0.0781=5.12\mathrm{KKg}/\mathrm{mol}\)

Q8 FREE PREVIEW
PYQ

Molality \(( m )\) of \(3 M\) aqueous solution of \(NaCl\) is

(Given : Density of solution \(=1.25 ~g mL ^{-1}\), Molar mass in \(g mol ^{-1}\) : \(\mathrm{Na}:23,\mathrm{Cl}:35.5\))

[JEE Main 2024, 6 Apr (Shift 2)]

a

\(2.90 \) m

b

\(2.79\) m

c

\(1.90\) m

d

\(3.85\) m

✓ Correct answer: b)

\(2.79\) m

Explanation

Molality \((m)\) is given as

\(m=\frac{{n}_{\text{solute }}}{k{g}_{\text{solvent }}}\)To calculate no. of moles of solute we take the help of molarity and to determine mass of solvent we take the help of density of solution. \(3 M\) solution of \(N a C l\) implies that there are 3 moles of \(N a C l\) in every 1 litre of solution. Considering \(1 L\) of solution, we have

\({n}_{\mathrm{NaCl}}=3\mathrm{mol}\)

Mass of \(1 L\) solution of \(\mathrm{NaCl}=(\) volume \()(\) density )

\(\begin{matrix} & =(1000\mathrm{mL})(1.25{\mathrm{gmol}}^{−1}) \\ & =1250\mathrm{g}\end{matrix}\)

Mass of NaCl in 1L of solution \(\begin{matrix} & =({n}_{\mathrm{NaCl}})({\mathrm{mm}}_{\mathrm{NaCl}})\end{matrix}\)

\(\begin{matrix} & =(3\mathrm{mol})(58.5{\mathrm{gmol}}^{−1}) \\ & =175.5\mathrm{g}\end{matrix}\)

Mass of solvent \(\left({\mathrm{H}}_{2}\mathrm{O}\right)=\) Mass of solution - Mass of solute \(=(1250\mathrm{g})-(175.5\mathrm{g})\)

\(=1074.5g\)

Thus

\(\begin{matrix} & m=\frac{{n}_{\text{solute}}}{{g}_{\text{solv}}}\frac{1000g}{kg} \\ & =\frac{3\mathrm{mol}}{1074.5g}\times \frac{1000g}{\mathrm{kg}} \\ & =2.79molk{g}^{-1}\end{matrix}\\\)

Alternatively \(m=\frac{{M}_{\text{soln }}}{1000d−{M}_{\text{soln }m{m}_{\text{solute }}}}\times 1000\)

\(\begin{matrix} & =\frac{3}{(1000)(1.25)−(3)(58.5)}\times 1000 \\ & =2.79{\mathrm{molkg}}^{−1}\end{matrix}\)

Q9 FREE PREVIEW
PYQ

Liquid A and B form an ideal solution. The vapour pressure of pure liquids A and B are \(350\) and\(750\)mm Hg respectively at the same temperature. If \({\mathrm{x}}_{\mathrm{A}}\) and \({x}_{B}\) are the mole fraction of A and B in solution while \({\mathrm{y}}_{\mathrm{A}}\) and \({y}_{B}\) are the mole fraction of A and B in vapour phase then

[JEE Main 2025, 7 Apr (Shift 2)]

a

\(\frac{{x}_{A}}{{x}_{B}}<\frac{{y}_{A}}{{y}_{B}}\)

b

\(\frac{{x}_{A}}{{x}_{B}}=\frac{{y}_{A}}{{y}_{B}}\)

c

\(\frac{{x}_{A}}{{x}_{B}}>\frac{{y}_{A}}{{y}_{B}}\)

d

\(\left({\mathrm{x}}_{\mathrm{A}}-{\mathrm{y}}_{\mathrm{A}}\right)<\left({\mathrm{x}}_{\mathrm{B}}-{\mathrm{y}}_{\mathrm{B}}\right)\)

✓ Correct answer: c)

\(\frac{{x}_{A}}{{x}_{B}}>\frac{{y}_{A}}{{y}_{B}}\)

Explanation

\({P}_{A}^{∘}<{P}_{B}^{∘}\Rightarrow \frac{{P}_{A}^{∘}}{{P}_{B}^{∘}}<1\)

\(\frac{{y}_{A}}{{y}_{B}}=\frac{{P}_{A}^{∘}{x}_{A}}{{P}_{B}^{∘}{x}_{B}}\)

\(\Rightarrow \frac{{y}_{A}}{{y}_{B}}<\frac{{x}_{A}}{{x}_{B}}\)

Q10 FREE PREVIEW
PYQ

\(\mathrm{HA}(\mathrm{aq})⇌{\mathrm{H}}^{+}(\mathrm{aq})+{\mathrm{A}}^{-}(\mathrm{aq})\)
The freezing point depression of a \(0.1\mathrm{m}\)aqueous solution of a monobasic weak acid HA is \(0.20^\circ \mathrm{C}\). The dissociation constant for the acid is
Given : \({\mathrm{K}}_{\mathrm{f}}\left({\mathrm{H}}_{2}\mathrm{O}\right)=1.8\mathrm{K}\mathrm{kg}{\mathrm{mol}}^{-1},\mathrm{molality}\equiv \mathrm{molarity}\)

[JEE Main 2025, 8 Apr (Shift 1)]

a

\(1.38\times {10}^{-3}\)

b

\(1.1\times {10}^{-2}\)

c

\(1.90\times {10}^{-3}\)

d

\(1.89\times {10}^{-1}\)

✓ Correct answer: a)

\(1.38\times {10}^{-3}\)

Explanation

ΔTf = ikfm

0.2 = i × 1.8 × 0.1

\(i=\frac{20}{18}=\frac{10}{9}\)

\(\begin{matrix}For & H{A}_{(aq)} & ⇌ & {H}_{(aq)}^{+} & + & {A}_{(aq)}^{−} \\ t=0 & 1 \\ t={t}_{eq} & 1−\alpha & & \alpha & & \alpha \end{matrix}\)

i = 1 + α

\(\frac{10}{9}=1+\alpha\)

\(\alpha =\frac{1}{9}\)

\({K}_{eq}=\frac{[{H}^{+}][{A}^{−}]}{[HA]}=\frac{C{\alpha }^{2}}{1−\alpha }\)

\(=\frac{0.1{(\frac{1}{9})}^{2}}{1−\frac{1}{9}}=\frac{1}{720}\)

\({K}_{eq.}=1.38\times {10}^{−3}\)

Q11 FREE PREVIEW
PYQ

The plots of \(\frac{1}{{\mathrm{X}}_{\mathrm{A}}}and\frac{1}{{Y}_{A}}(where{\mathrm{X}}_{\mathrm{A}}\mathrm{and}{\mathrm{Y}}_{\mathrm{A}}\mathrm{are}\mathrm{the}\mathrm{mole}\mathrm{fraction}\mathrm{of}\mathrm{liquid}\mathrm{A}\mathrm{in}\mathrm{liquid}\mathrm{and}\mathrm{vapour}\mathrm{phase}\mathrm{respectively})\) is linear with slope and intercepts respectively

(Memory Based JEE Mains 23/01/2025 ,Shift -2)

a

\({{\mathrm{P}}_{\mathrm{A}}}^{0}/{{\mathrm{P}}_{\mathrm{B}}}^{0}\mathrm{and}\frac{{{\mathrm{P}}_{\mathrm{A}}}^{0}-{{\mathrm{P}}_{\mathrm{B}}}^{0}}{{{\mathrm{P}}_{\mathrm{B}}}^{0}}\)

b

\({{\mathrm{P}}_{\mathrm{A}}}^{0}/{{\mathrm{P}}_{\mathrm{B}}}^{0}\mathrm{and}\frac{{{\mathrm{P}}_{\mathrm{B}}}^{0}-{{\mathrm{P}}_{\mathrm{A}}}^{0}}{{{\mathrm{P}}_{\mathrm{B}}}^{0}}\)

c

\({{\mathrm{P}}_{\mathrm{B}}}^{0}/{{\mathrm{P}}_{\mathrm{A}}}^{0}\mathrm{and}\frac{{{\mathrm{P}}_{\mathrm{A}}}^{0}-{{\mathrm{P}}_{\mathrm{B}}}^{0}}{{{\mathrm{P}}_{\mathrm{B}}}^{0}}\)

d

\({{\mathrm{P}}_{\mathrm{B}}}^{0}/{{\mathrm{P}}_{\mathrm{A}}}^{0}\mathrm{and}\frac{{{\mathrm{P}}_{\mathrm{B}}}^{0}-{{\mathrm{P}}_{\mathrm{A}}}^{0}}{{{\mathrm{P}}_{\mathrm{B}}}^{0}}\)

✓ Correct answer: b)

\({{\mathrm{P}}_{\mathrm{A}}}^{0}/{{\mathrm{P}}_{\mathrm{B}}}^{0}\mathrm{and}\frac{{{\mathrm{P}}_{\mathrm{B}}}^{0}-{{\mathrm{P}}_{\mathrm{A}}}^{0}}{{{\mathrm{P}}_{\mathrm{B}}}^{0}}\)

Explanation

By the Rault's law

\({\mathrm{P}}_{\mathrm{A}}={\mathrm{P}}_{\mathrm{A}}^{\mathrm{o}}{\mathrm{X}}_{\mathrm{A}}....(1)\\ {\mathrm{P}}_{\mathrm{B}}={\mathrm{P}}_{\mathrm{B}}^{\mathrm{o}}{\mathrm{X}}_{\mathrm{B}}.....(2)\\ \mathrm{Now}\\ {\mathrm{P}}_{\mathrm{A}}={\mathrm{Y}}_{\mathrm{A}}{\mathrm{P}}_{\mathrm{T}}\Rightarrow {\mathrm{P}}_{\mathrm{T}}=\frac{{\mathrm{P}}_{\mathrm{A}}}{{\mathrm{Y}}_{\mathrm{A}}}\\ {\mathrm{P}}_{\mathrm{B}}={\mathrm{Y}}_{\mathrm{B}}{\mathrm{P}}_{\mathrm{T}}\Rightarrow {\mathrm{P}}_{\mathrm{T}}=\frac{{\mathrm{P}}_{\mathrm{B}}}{{\mathrm{Y}}_{\mathrm{B}}}\\ \frac{{\mathrm{P}}_{\mathrm{A}}}{{\mathrm{Y}}_{\mathrm{A}}}=\frac{{\mathrm{P}}_{\mathrm{B}}}{{\mathrm{Y}}_{\mathrm{B}}}\\ \frac{{\mathrm{P}}_{\mathrm{A}}^{\mathrm{o}}{\mathrm{X}}_{\mathrm{A}}}{{\mathrm{Y}}_{\mathrm{A}}}=\frac{{\mathrm{P}}_{\mathrm{B}}^{\mathrm{o}}{\mathrm{X}}_{\mathrm{B}}}{{\mathrm{Y}}_{\mathrm{B}}}\left(\mathrm{From}\left(1\right)\mathrm{and}\left(2\right)\right)\\ \frac{{\mathrm{P}}_{\mathrm{A}}^{\mathrm{o}}{\mathrm{X}}_{\mathrm{A}}}{{\mathrm{Y}}_{\mathrm{A}}}=\frac{{\mathrm{P}}_{\mathrm{B}}^{\mathrm{o}}\left(1-{\mathrm{X}}_{\mathrm{A}}\right)}{1-{\mathrm{Y}}_{\mathrm{A}}}\\ \frac{{\mathrm{P}}_{\mathrm{A}}^{\mathrm{o}}\left(1-{\mathrm{Y}}_{\mathrm{A}}\right)}{{\mathrm{Y}}_{\mathrm{A}}}=\frac{{\mathrm{P}}_{\mathrm{B}}^{\mathrm{o}}\left(1-{\mathrm{X}}_{\mathrm{A}}\right)}{{\mathrm{X}}_{\mathrm{A}}}\\ \frac{{\mathrm{P}}_{\mathrm{A}}^{\mathrm{o}}}{{\mathrm{Y}}_{\mathrm{A}}}-\frac{{\mathrm{P}}_{\mathrm{A}}^{\mathrm{o}}{\mathrm{Y}}_{\mathrm{A}}}{{\mathrm{Y}}_{\mathrm{A}}}=\frac{{\mathrm{P}}_{\mathrm{B}}^{\mathrm{o}}}{{\mathrm{X}}_{\mathrm{A}}}-\frac{{\mathrm{P}}_{\mathrm{B}}^{\mathrm{o}}{\mathrm{X}}_{\mathrm{A}}}{{\mathrm{X}}_{\mathrm{A}}}\\ \frac{{\mathrm{P}}_{\mathrm{B}}^{\mathrm{o}}}{{\mathrm{X}}_{\mathrm{A}}}=\frac{{\mathrm{P}}_{\mathrm{A}}^{\mathrm{o}}}{{\mathrm{Y}}_{\mathrm{A}}}+\left({\mathrm{P}}_{\mathrm{B}}^{\mathrm{o}}-{\mathrm{P}}_{\mathrm{A}}^{\mathrm{o}}\right)\\ \frac{1}{{\mathrm{X}}_{\mathrm{A}}}=\frac{1}{{\mathrm{Y}}_{\mathrm{A}}}\left(\frac{{\mathrm{P}}_{\mathrm{A}}^{\mathrm{o}}}{{\mathrm{P}}_{\mathrm{B}}^{\mathrm{o}}}\right)+\frac{\left({\mathrm{P}}_{\mathrm{B}}^{\mathrm{o}}-{\mathrm{P}}_{\mathrm{A}}^{\mathrm{o}}\right)}{{\mathrm{P}}_{\mathrm{B}}^{\mathrm{o}}}\\ \mathrm{Compare}\mathrm{with}\mathrm{y}=\mathrm{mx}+\mathrm{c}\)

Q12 FREE PREVIEW
PYQ

58.5 g of NaCl and 180 g of glucose were separately dissolved in 1000 mL of water.Identify the correct statement regarding the elevation of boiling point of the resulting solution.

a

NaCl solution will show higher elevation of boiling point.

b

Glucose solution will show higher elevation of boiling point.

c

Both solutions will show equal elevation of boiling point.

d

None will show boiling point elevation.

✓ Correct answer: a)

NaCl solution will show higher elevation of boiling point.

Explanation

Boiling point elevation depends on molality × van’t Hoff factor (i). NaCl (i = 2) dissociates, while glucose (i = 1) does not. Thus, NaCl solution shows higher elevation.

Q13 FREE PREVIEW
PYQ

Which of the following binary mixture does not show the behaviour of minimum boiling azeotropes?

[JEE Main 2025, 8 Apr (Shift 1)]

a

\({\mathrm{H}}_{2}\mathrm{O}+{\mathrm{CH}}_{3}{\mathrm{COC}}_{2}{\mathrm{H}}_{5}\)

b

\({\mathrm{C}}_{6}{\mathrm{H}}_{5}\mathrm{OH}+{\mathrm{C}}_{6}{\mathrm{H}}_{5}{\mathrm{NH}}_{2}\)

c

\({\mathrm{CS}}_{2}+{\mathrm{CH}}_{3}{\mathrm{COCH}}_{3}\)

d

\({\mathrm{CH}}_{3}\mathrm{OH}+{\mathrm{CHCl}}_{3}\)

✓ Correct answer: b)

\({\mathrm{C}}_{6}{\mathrm{H}}_{5}\mathrm{OH}+{\mathrm{C}}_{6}{\mathrm{H}}_{5}{\mathrm{NH}}_{2}\)

Explanation

Binary mixture of C6H5OH and C6H5NH2 shows negative deviation from Raoult's law. So, vapour pressure of solution is less than V.P of pure C6H5OH and C6H5NH2. So, B.P. of solution is greater than boiling point of pure C6H5OH and C6H5NH2. So mixture shows maximum Boiling azeotrope

Q14
PYQ

Considering acetic acid dissociates in water, its dissociation constant is \(6.25\times {10}^{-5}\) . If \(5\mathrm{ml}\) 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 \(0^\circ C\). \(x=\)________
Given: \({\left({K}_{f}\right)}_{\text{water }}=1.86Kkgmo{l}^{-1}\text{. }\)

Density of acetic acid is 1.2 g mL–1.

molar mass of water = 18 g mol–1.

molar mass of acetic acid = 60 g mol–1.

density of water = 1 g cm–3

Acetic acid dissociates as

\({\mathrm{CH}}_{3}\mathrm{COOH}⇌{\mathrm{CH}}_{3}{\mathrm{COO}}^{-}+{\mathrm{H}}^{+}\)

a

11

b

19

c

22

d

25

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Q15
PYQ

Considering acetic acid dissociates in water, its dissociation constant is \(6.25\times {10}^{-5}\) . If \(5\mathrm{ml}\) 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 \(0^\circ C\). \(x=\)________
Given: \({\left({K}_{f}\right)}_{\text{water }}=1.86Kkgmo{l}^{-1}\text{. }\)

Density of acetic acid is 1.2 g mL–1.

molar mass of water = 18 g mol–1.

molar mass of acetic acid = 60 g mol–1.

density of water = 1 g cm–3

Acetic acid dissociates as

\({\mathrm{CH}}_{3}\mathrm{COOH}⇌{\mathrm{CH}}_{3}{\mathrm{COO}}^{-}+{\mathrm{H}}^{+}\)

a

11

b

19

c

22

d

25

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Q16
PYQ

If a substance ' \(A\) ' dissolves in solution of a mixture of ' \(B\) ' and ' \(C\) ' with their respective number of moles as \(n _{ A }, n _{ B }\) and \(n _{ C }\). Mole fraction of \(C\) in the solution is

[JEE Main 2024, 30 Jan (Shift 2)]

a

\(\frac{n_C}{n_A-n_B-n_C}\)

b

\(\frac{n_C}{n_A \times n_B \times n_C}\)

c

\(\frac{ n _{ B }}{ n _{ A }+ n _{ B }}\)

d

\(\frac{n_C}{n_A+n_B+n_C}\)

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Q17
PYQ

If a substance ' \(A\) ' dissolves in solution of a mixture of ' \(B\) ' and ' \(C\) ' with their respective number of moles as \(n _{ A }, n _{ B }\) and \(n _{ C }\). Mole fraction of \(C\) in the solution is

[JEE Main 2024, 30 Jan (Shift 2)]

a

\(\frac{n_C}{n_A-n_B-n_C}\)

b

\(\frac{n_C}{n_A \times n_B \times n_C}\)

c

\(\frac{ n _{ B }}{ n _{ A }+ n _{ B }}\)

d

\(\frac{n_C}{n_A+n_B+n_C}\)

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Q18
PYQ

What is the freezing point depression constant of a solvent, 50 g of which contain 1 g non volatile solute (molar mass \(256gmo{l}^{-1}\) ) and the decrease in freezing point is 0.40 K ?

[JEE Main 2025, 28 Jan (Shift 1)]

a

\(5.12\mathrm{K}\mathrm{kg}{\mathrm{mol}}^{-1}\)

b

\(3.72\mathrm{K}\mathrm{kg}{\mathrm{mol}}^{-1}\)

c

\(4.43\mathrm{K}\mathrm{kg}{\mathrm{mol}}^{-1}\)

d

\(1.86\mathrm{K}\mathrm{kg}{\mathrm{mol}}^{-1}\)

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Q19
PYQ

Arrange the following aqueous solutions in order of their increasing boiling points

\(\left(\mathrm{i}\right){10}^{-4}\mathrm{M}\mathrm{NaCl}\\ \left(\mathrm{ii}\right){10}^{-4}\mathrm{M}\mathrm{Urea}\\ \left(\mathrm{iii}\right){10}^{-3}\mathrm{M}\mathrm{NaCl}\\ \left(\mathrm{iv}\right){10}^{-2}\mathrm{M}\mathrm{NaCl}\)

a

(ii) < (i) = (iii) < (iv)

b

(iv) < (iii) < (i) < (ii)

c

(ii) < (i) < (iii) < (iv)

d

(i) < (ii) < (iii) < (iv)

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Q20
PYQ

The quantity which changes with temperature is:

[JEE Main 2024, 27 Jan (Shift 2)]

a

Mass percentage

b

Molality

c

Molarity

d

Mole fraction

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Q21
PYQ

The quantity which changes with temperature is:

[JEE Main 2024, 27 Jan (Shift 2)]

a

Mass percentage

b

Molality

c

Molarity

d

Mole fraction

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Q22
PYQ

Assume a living cell with \(0.9\%(\omega /\omega )\) of glucose solution (aqueous). This cell is immersed in another solution having equal mole fraction of glucose and water.
(Consider the data upto first decimal place only)
The cell will

[JEE Main 2025, 28 Jan (Shift 2)]

a

show no change in volume since solution is \(0.9\%(\omega /\omega )\)

b

shrink since solution is \(0.45\%(\omega /\omega )\) as a result of association of glucose molecules (due to hydrogen bonding)

c

shrink since solution is 90% \((\omega /\omega )\)

d

swell up since solution is \(1\%(\omega /\omega )\)

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Q23
PYQ

The Molarity (M) of an aqueous solution containing \(5.85\mathrm{g}\) of \(\mathrm{NaCl}\) in \(500\mathrm{mL}\) water is (Given : Molar Mass \(\mathrm{Na}\): \(23\) and \(Cl:35.5gmo{l}^{-1}\))

[JEE Main 2024, 4 Apr (Shift 1)]

a

0.2

b

4

c

20

d

2

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Q24
PYQ

What is the value of van't Hoff Factor for \({\mathrm{A}}_{2}\mathrm{B}\) if 30% of \({\mathrm{A}}_{2}\mathrm{B}\) is dissociated?

a

1.60

b

1.30

c

1.50

d

1.20

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Q25
PYQ

The molarity of \(1\mathrm{L}\) orthophosphoric acid \(\left({\mathrm{H}}_{3}{\mathrm{PO}}_{4}\right)\) having 70 % purity by weight (specific gravity \(1.54\mathrm{g}{\mathrm{cm}}^{-3}\)) is _____ \(\mathrm{M}\)
(Molar mass of \({\mathrm{H}}_{3}{\mathrm{PO}}_{4}=98\mathrm{g}{\mathrm{mol}}^{-1}\) )

[JEE Main 2024, 31 Jan (Shift 2)]

a

11

b

10

c

12

d

9

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Q26
PYQ

Given below are two statements :
Statement (I) : NaCl is added to the ice at \(0^\circ C\), present in the ice cream box to prevent the melting of ice cream.
Statement (II) : On addition of NaCl to ice at \(0^\circ C\), there is a depression in freezing point.
In the light of the above statements, choose the correct answer from the options given below

[JEE Main 2025, 29 Jan (Shift 2)]

a

Both Statement I and Statement II are false

b

Both Statement I and Statement II are true

c

Statement I is false but Statement II is true

d

Statement I is true but Statement II is false

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Q27
PYQ

Arrange the following solutions in order of their increasing boiling points

\(\left(\mathrm{i}\right){10}^{-4}\mathrm{M}\mathrm{NaCl}\\ \left(\mathrm{ii}\right){10}^{-4}\mathrm{M}\mathrm{Urea}\\ \left(\mathrm{iii}\right){10}^{-3}\mathrm{M}\mathrm{NaCl}\\ \left(\mathrm{iv}\right){10}^{-2}\mathrm{M}\mathrm{NaCl}\)

a

(ii) < (i) = (iii) < (iv)

b

(iv) < (iii) < (i) < (ii)

c

(ii) < (i) < (iii) < (iv)

d

(i) < (ii) < (iii) < (iv)

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Q28
PYQ

The plots of \(\frac{1}{{\mathrm{X}}_{\mathrm{A}}}and\frac{1}{{Y}_{A}}(where{\mathrm{X}}_{\mathrm{A}}\mathrm{and}{\mathrm{Y}}_{\mathrm{A}}\mathrm{are}\mathrm{the}\mathrm{mole}\mathrm{fraction}\mathrm{of}\mathrm{liquid}\mathrm{A}\mathrm{in}\mathrm{liquid}\mathrm{and}\mathrm{vapour}\mathrm{phase}\mathrm{respectively})\) is linear with slope and intercepts respectively

(Memory Based JEE Mains 23/01/2025 ,Shift -2)

a

\({{\mathrm{P}}_{\mathrm{A}}}^{0}/{{\mathrm{P}}_{\mathrm{B}}}^{0}\mathrm{and}\frac{{{\mathrm{P}}_{\mathrm{A}}}^{0}-{{\mathrm{P}}_{\mathrm{B}}}^{0}}{{{\mathrm{P}}_{\mathrm{B}}}^{0}}\)

b

\({{\mathrm{P}}_{\mathrm{A}}}^{0}/{{\mathrm{P}}_{\mathrm{B}}}^{0}\mathrm{and}\frac{{{\mathrm{P}}_{\mathrm{B}}}^{0}-{{\mathrm{P}}_{\mathrm{A}}}^{0}}{{{\mathrm{P}}_{\mathrm{B}}}^{0}}\)

c

\({{\mathrm{P}}_{\mathrm{B}}}^{0}/{{\mathrm{P}}_{\mathrm{A}}}^{0}\mathrm{and}\frac{{{\mathrm{P}}_{\mathrm{A}}}^{0}-{{\mathrm{P}}_{\mathrm{B}}}^{0}}{{{\mathrm{P}}_{\mathrm{B}}}^{0}}\)

d

\({{\mathrm{P}}_{\mathrm{B}}}^{0}/{{\mathrm{P}}_{\mathrm{A}}}^{0}\mathrm{and}\frac{{{\mathrm{P}}_{\mathrm{B}}}^{0}-{{\mathrm{P}}_{\mathrm{A}}}^{0}}{{{\mathrm{P}}_{\mathrm{B}}}^{0}}\)

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Q29
PYQ

A solution containing 10 g of an electrolyte in 100 g of water boils at \(100.52{}^{\mathrm{o}}\mathrm{C}\). The degree of ionization of the electrolyte is \(x\times {10}^{-1}\) (nearest integer)
[Given : Molar mass of \(AB _2=200 ~g mol ^{-1}, K _{ b }\) (molal boiling point elevation const. of water) \(=0.52 ~K kg mol ^{-1}\), boiling point of water \(=100^{\circ} C ; AB _2\) ionises as \(\left.AB _2 \rightarrow A ^{2+}+2 B ^{-}\right]\)

[JEE Main 2024, 08 Apr (Shift 1)]

a

3

b

4

c

5

d

6

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Q30
PYQ

A solution containing 10 g of an electrolyte in 100 g of water boils at \(100.52{}^{\mathrm{o}}\mathrm{C}\). The degree of ionization of the electrolyte is \(x\times {10}^{-1}\) (nearest integer)
[Given : Molar mass of \(AB _2=200 ~g mol ^{-1}, K _{ b }\) (molal boiling point elevation const. of water) \(=0.52 ~K kg mol ^{-1}\), boiling point of water \(=100^{\circ} C ; AB _2\) ionises as \(\left.AB _2 \rightarrow A ^{2+}+2 B ^{-}\right]\)

[JEE Main 2024, 08 Apr (Shift 1)]

a

3

b

4

c

5

d

6

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Q31
PYQ

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)

[JEE Main 2024, 08 Apr (Shift 2)]

a

74

b

75

c

76

d

80

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Q32
PYQ

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)

[JEE Main 2024, 08 Apr (Shift 2)]

a

74

b

75

c

76

d

80

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Q33
PYQ

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)

[JEE Main 2024, 08 Apr (Shift 2)]

a

74

b

75

c

76

d

80

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Q34
PYQ

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

[JEE Main 2024, 30 Jan (Shift 1)]

a

First decreases and then increases

b

Decreases

c

Increases

d

Remains unchanged

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Q35
PYQ

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

[JEE Main 2024, 30 Jan (Shift 1)]

a

First decreases and then increases

b

Decreases

c

Increases

d

Remains unchanged

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Q36
PYQ

Proceess in non spontaneous at freezing point but spontaneous at boiling point, find ΔH and ΔS ?

a

Both are positive

b

Both are negative

c

ΔS Positive and Negative ΔH

d

ΔS Negative and ΔH Positive.

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Q37
PYQ

An artificial cell is made by encapsulating \(0.2\mathrm{M}\) glucose solution within a semipermeable membrane. The osmotic pressure developed when the artificial cell is placed within a \(0.05\mathrm{M}\) solution of \(\mathrm{NaCl}\) at \(300\mathrm{K}\) is _______ \(\times {10}^{-1}\) bar. (nearest integer).
[Given : \(R=0.083Lbarmo{l}^{-1}{K}^{-1}\)]
Assume complete dissociation of \(\mathrm{NaCl}\)

[JEE Main 2024, 5 Apr (Shift 1)]

a

25

b

35

c

45

d

65

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Q38
PYQ

Which of the following binary mixture does not show the behaviour of minimum boiling azeotropes?

[JEE Main 2025, 8 Apr (Shift 1)]

a

\({\mathrm{H}}_{2}\mathrm{O}+{\mathrm{CH}}_{3}{\mathrm{COC}}_{2}{\mathrm{H}}_{5}\)

b

\({\mathrm{C}}_{6}{\mathrm{H}}_{5}\mathrm{OH}+{\mathrm{C}}_{6}{\mathrm{H}}_{5}{\mathrm{NH}}_{2}\)

c

\({\mathrm{CS}}_{2}+{\mathrm{CH}}_{3}{\mathrm{COCH}}_{3}\)

d

\({\mathrm{CH}}_{3}\mathrm{OH}+{\mathrm{CHCl}}_{3}\)

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Q39
PYQ

30gm \({\mathrm{HNO}}_{3}\)is added to a solution to prepare 75 % w/ w solution having density 1.25 g / mL. Volume of solution is?

Memory Based Question 28/Jan/25 Evening shift

a

32 ml

b

48 ml

c

36 ml

d

28 ml

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Q40
PYQ

Molarity (M) of an aqueous solution containing \(x \mathrm{~g}\) of anhyd. \(\mathrm{CuSO}_4\) in \(500 \mathrm{~mL}\) solution at \(32^{\circ} \mathrm{C}\) is \(2 \times 10^{-1} \mathrm{M}\). Its molality will be_____ \(\times 10^{-3} \mathrm{~m}\). (nearest integer). [Given density of the solution \(=1.25 \mathrm{~g} / \mathrm{mL}\) ]

[JEE Main 2024, 9 Apr (Shift 1)]

a

164

b

165

c

155

d

None

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Q41
PYQ

\(\mathrm{HA}(\mathrm{aq})⇌{\mathrm{H}}^{+}(\mathrm{aq})+{\mathrm{A}}^{-}(\mathrm{aq})\)
The freezing point depression of a \(0.1\mathrm{m}\)aqueous solution of a monobasic weak acid HA is \(0.20^\circ \mathrm{C}\). The dissociation constant for the acid is
Given : \({\mathrm{K}}_{\mathrm{f}}\left({\mathrm{H}}_{2}\mathrm{O}\right)=1.8\mathrm{K}\mathrm{kg}{\mathrm{mol}}^{-1},\mathrm{molality}\equiv \mathrm{molarity}\)

[JEE Main 2025, 8 Apr (Shift 1)]

a

\(1.38\times {10}^{-3}\)

b

\(1.1\times {10}^{-2}\)

c

\(1.90\times {10}^{-3}\)

d

\(1.89\times {10}^{-1}\)

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Q42
PYQ

The Henry's law constant \(\left({\mathrm{K}}_{\mathrm{H}}\right)\) values of three gases (A, B, C) in water are \(145,2\times {10}^{-5}\) and \(35\mathrm{kbar}\), respectively. The solubility of these gases in water follow the order

[NEET 2024]

a

\(\mathrm{A}>\mathrm{B}>\mathrm{C}\)

b

\(\mathrm{B}>\mathrm{A}>\mathrm{C}\)

c

\(\mathrm{B}>\mathrm{C}>\mathrm{A}\)

d

\(\mathrm{A}>\mathrm{C}>\mathrm{B}\)

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Q43
PYQ

Mass of ethylene glycol (antifreeze) to be added to \(18.6 ~kg\) of water to protect the freezing point at \(-24^\circ C\) is____________ \(kgmo{l}^{-1}\) (Round off to nearest integer) (Molar mass in \(gmo{l}^{-1}\) for ethylene glycol \(=62) ( K _f\) of water \(=1.86Kkgmo{l}^{-1}\)

[JEE Main 2024, 1 Feb (Shift 2)]

a

15

b

30

c

45

d

60

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Q44
PYQ

58.5 g of NaCl and 180 g of glucose were separately dissolved in 1000 mL of water.Identify the correct statement regarding the elevation of boiling point of the resulting solution.

a

NaCl solution will show higher elevation of boiling point.

b

Glucose solution will show higher elevation of boiling point.

c

Both solutions will show equal elevation of boiling point.

d

None will show boiling point elevation.

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Q45
PYQ

200 ml of 0.2 M NaOH is mixed with 400 ml of 0.5 M NaOH solution. Molarity of mixture is:

a

0.4

b

0.6

c

4.0

d

0.8

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Q46
PYQ

In which mode of expression, the concentration of a solution remains independent of temperature?

a

Molarity

b

Normality

c

Formality

d

Molality

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Q47
PYQ

What is the value of van't Hoff Factor for \({\mathrm{A}}_{2}\mathrm{B}\) if 30% of \({\mathrm{A}}_{2}\mathrm{B}\) is dissociated?

a

1.60

b

1.30

c

1.50

d

1.20

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Q48
PYQ

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 decrease in vapour pressure is 20 mm Hg?

[JEE Main 2025, 23 Jan (Shift 2)]

a

0.2

b

0.6

c

0.4

d

0.8

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Q49
PYQ

2 moles each of ethylene glycol and glucose are dissolved in 500 g of water. The boiling point of the resulting solution is
(Given : Ebullioscopic constant of water \(=0.52\mathrm{K}\mathrm{kg}{\mathrm{mol}}^{-1}\))

[JEE Main 2025, 3 Apr (Shift 1)]

a

379.2 K

b

377.3 K

c

375.3 K

d

277.3 K

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Q50
PYQ

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 decrease in vapour pressure is 20 mm Hg?

[JEE Main 2025, 23 Jan (Shift 2)]

a

0.2

b

0.6

c

0.4

d

0.8

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Q51
PYQ

1.24 g of \(A{X}_{2}\) (molar mass \(124gmo{l}^{-1}\)) is dissolved in 1 kg of water to form a solution with boiling point of \(100.0156^\circ C\), while 25.4 g of \(A{Y}_{2}\) (molar mass \(250gmo{l}^{-1}\)) in 2 kg of water constitutes a solution with a boiling point of \(100.0260^\circ C\).

\({K}_{b}\left({H}_{2}O\right)=0.52Kkgmo{l}^{-1}\)

Which of the following is correct ?

[JEE Main 2025, 29 Jan (Shift 1)]

a

\(A{X}_{2}\) and \(A{Y}_{2}\) (both) are completely unionised.

b

\(A{X}_{2}\) is fully ionised while \(A{Y}_{2}\) is completely unionised.

c

\(A{X}_{2}\) and \(A{Y}_{2}\) (both) are fully ionised.

d

\(A{X}_{2}\) is completely unionised while \(A{Y}_{2}\) is fully ionised.

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Q52
PYQ

In which mode of expression, the concentration of a solution remains independent of temperature?

a

Molarity

b

Normality

c

Formality

d

Molality

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Q53
PYQ

The density of ' \(x\) ' \(\mathrm{M}\) solution (' \(x\) ' molar) of \(\mathrm{NaOH}\) is \(1.12\mathrm{g}{\mathrm{mL}}^{-1}\), while in molality, the concentration of the solution is \(3\mathrm{m}(3\mathrm{molal})\). Then \(x\) is
(Given : Molar mass of \(\mathrm{NaOH}\) is \(40\mathrm{g}/\mathrm{mol}\) )

[JEE Main 2024, 6 Apr (Shift 1)]

a

3.8

b

3.5

c

2.8

d

3.0

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Q54
PYQ

Arrange the following solutions in order of their increasing boiling points

\(\left(\mathrm{i}\right){10}^{-4}\mathrm{M}\mathrm{NaCl}\\ \left(\mathrm{ii}\right){10}^{-4}\mathrm{M}\mathrm{Urea}\\ \left(\mathrm{iii}\right){10}^{-3}\mathrm{M}\mathrm{NaCl}\\ \left(\mathrm{iv}\right){10}^{-2}\mathrm{M}\mathrm{NaCl}\)

a

(ii) < (i) = (iii) < (iv)

b

(iv) < (iii) < (i) < (ii)

c

(ii) < (i) < (iii) < (iv)

d

(i) < (ii) < (iii) < (iv)

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Q55
PYQ

Which of the following binary mixture does not show the behaviour of minimum boiling azeotropes?

[JEE Main 2025, 8 Apr (Shift 1)]

a

\({\mathrm{H}}_{2}\mathrm{O}+{\mathrm{CH}}_{3}{\mathrm{COC}}_{2}{\mathrm{H}}_{5}\)

b

\({\mathrm{C}}_{6}{\mathrm{H}}_{5}\mathrm{OH}+{\mathrm{C}}_{6}{\mathrm{H}}_{5}{\mathrm{NH}}_{2}\)

c

\({\mathrm{CS}}_{2}+{\mathrm{CH}}_{3}{\mathrm{COCH}}_{3}\)

d

\({\mathrm{CH}}_{3}\mathrm{OH}+{\mathrm{CHCl}}_{3}\)

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Q56
PYQ

What is the freezing point depression constant of a solvent, 50 g of which contain 1 g non volatile solute (molar mass \(256gmo{l}^{-1}\) ) and the decrease in freezing point is 0.40 K ?

[JEE Main 2025, 28 Jan (Shift 1)]

a

\(5.12\mathrm{K}\mathrm{kg}{\mathrm{mol}}^{-1}\)

b

\(3.72\mathrm{K}\mathrm{kg}{\mathrm{mol}}^{-1}\)

c

\(4.43\mathrm{K}\mathrm{kg}{\mathrm{mol}}^{-1}\)

d

\(1.86\mathrm{K}\mathrm{kg}{\mathrm{mol}}^{-1}\)

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Q57
PYQ

What is the freezing point depression constant of a solvent, 50 g of which contain 1 g non volatile solute (molar mass \(256gmo{l}^{-1}\) ) and the decrease in freezing point is 0.40 K ?

[JEE Main 2025, 28 Jan (Shift 1)]

a

\(5.12\mathrm{K}\mathrm{kg}{\mathrm{mol}}^{-1}\)

b

\(3.72\mathrm{K}\mathrm{kg}{\mathrm{mol}}^{-1}\)

c

\(4.43\mathrm{K}\mathrm{kg}{\mathrm{mol}}^{-1}\)

d

\(1.86\mathrm{K}\mathrm{kg}{\mathrm{mol}}^{-1}\)

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Q58
PYQ

Consider the dissociation of the weak acid \(\mathrm{HX}\) as given below
\(\mathrm{HX}(\mathrm{aq})⇌{\mathrm{H}}^{+}(\mathrm{aq})+{\mathrm{X}}^{-}(\mathrm{aq}),\mathrm{Ka}=1.2\times {10}^{-5}\)
\(\left[{\mathrm{K}}_{\mathrm{a}}\right.\) : dissociation constant]
The osmotic pressure of \(0.03\mathrm{M}\) aqueous solution of \(\mathrm{HX}\) at \(300\mathrm{K}\) is ___ \(\times {10}^{-2}\) bar (nearest integer)
[Given : \(\mathrm{R}=0.083{\mathrm{Lbarmol}}^{-1}{\mathrm{K}}^{-1}\) ]

[JEE Main 2024, 6 Apr (Shift 1)]

a

76

b

67

c

57

d

26

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Q59
PYQ

Given below are two statements :
Statement (I) : NaCl is added to the ice at \(0^\circ C\), present in the ice cream box to prevent the melting of ice cream.
Statement (II) : On addition of NaCl to ice at \(0^\circ C\), there is a depression in freezing point.
In the light of the above statements, choose the correct answer from the options given below

a

Both Statement I and Statement II are false

b

Both Statement I and Statement II are true

c

Statement I is false but Statement II is true

d

Statement I is true but Statement II is false

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Q60
PYQ

A solution is made by mixing one mole of volatile liquid A with \(3\) moles of volatile liquid B. The vapour pressure of pure A is 200 mm Hg and that of the solution is \(500\) mm Hg . The vapour pressure of pure B and the least volatile component of the solution, respectively, are

a

\(1400\mathrm{mmHg},\mathrm{A}\)

b

\(1400\mathrm{mmHg},\mathrm{B}\)

c

\(600\mathrm{mmHg},\mathrm{B}\)

d

\(600\mathrm{mmHg},\mathrm{A}\)

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Q61
PYQ

Compare boiling point of given solutions:

(Memory Based JEE Mains 22/01/2025 Shift-1)
\((\mathrm{i}){10}^{-4}\mathrm{M}\mathrm{NaCl}\\ (\mathrm{ii}){10}^{-3}\mathrm{M}\mathrm{NaCl}\\ (\mathrm{iii}){10}^{-2}\mathrm{M}\mathrm{NaCl}\\ (\mathrm{iv}){10}^{-4}\mathrm{M}\mathrm{Urea}\)

a

I > II >III > IV

b

III > II > I > IV

c

II > I > III > IV

d

III > I> II > IV

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Q62
PYQ

2 moles each of ethylene glycol and glucose are dissolved in 500 g of water. The boiling point of the resulting solution is
(Given : Ebullioscopic constant of water \(=0.52\mathrm{K}\mathrm{kg}{\mathrm{mol}}^{-1}\))

[JEE Main 2025, 3 Apr (Shift 1)]

a

379.2 K

b

377.3 K

c

375.3 K

d

277.3 K

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Q63
PYQ

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

[JEE Main 2024, 30 Jan (Shift 2)]

a

180 g of glucose dissolved in water

b

180 g of acetic acid dissolved in water

c

180 g of acetic acid dissolved in benzene.

d

180 g of benzoic acid dissolved in benzene

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Q64
PYQ

Proceess in non spontaneous at freezing point but spontaneous at boiling point, find ΔH and ΔS ?

a

Both are positive

b

Both are negative

c

ΔS Positive and Negative ΔH

d

ΔS Negative and ΔH Positive.

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Q65
PYQ

The Molarity (M) of an aqueous solution containing \(5.85\mathrm{g}\) of \(\mathrm{NaCl}\) in \(500\mathrm{mL}\) water is (Given : Molar Mass \(\mathrm{Na}\): \(23\) and \(Cl:35.5gmo{l}^{-1}\))

[JEE Main 2024, 4 Apr (Shift 1)]

a

0.2

b

4

c

20

d

2

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Q66
PYQ

A solution is prepared by adding 1 mole ethyl alcohol in 9 mole water. The mass percent of solute in the solution is ....... (Integer answer) (Given : Molar mass in \(g mol ^{-1}\) Ethyl alcohol : \(46\) water: \(18\)\()\)

[JEE Main 2024, 08 Apr (Shift 2)]

a

22

b

16

c

20

d

15

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Q67
PYQ

A solution is prepared by adding 1 mole ethyl alcohol in 9 mole water. The mass percent of solute in the solution is ....... (Integer answer) (Given : Molar mass in \(g mol ^{-1}\) Ethyl alcohol : \(46\) water: \(18\)\()\)

[JEE Main 2024, 08 Apr (Shift 2)]

a

22

b

16

c

20

d

15

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Q68
PYQ

Molality of \(0.8 M ~H _2 SO _4\) solution (density \(1.06{\mathrm{gcm}}^{-3}\)) is ______ \(\times 10^{-3} m\). (Nearest Integer)

[JEE Main 2024, 29 Jan (Shift 2)]

a

815

b

800

c

813

d

810

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Q69
PYQ

1.24 g of \(A{X}_{2}\) (molar mass \(124gmo{l}^{-1}\)) is dissolved in 1 kg of water to form a solution with boiling point of \(100.0156^\circ C\), while 25.4 g of \(A{Y}_{2}\) (molar mass \(250gmo{l}^{-1}\)) in 2 kg of water constitutes a solution with a boiling point of \(100.0260^\circ C\).

\({K}_{b}\left({H}_{2}O\right)=0.52Kkgmo{l}^{-1}\)

Which of the following is correct ?

a

\(A{X}_{2}\) and \(A{Y}_{2}\) (both) are completely unionised.

b

\(A{X}_{2}\) is fully ionised while \(A{Y}_{2}\) remain unionised.

c

\(A{X}_{2}\) and \(A{Y}_{2}\) (both) are fully ionised.

d

\(A{X}_{2}\) is completely unionised while \(A{Y}_{2}\) is fully ionised.

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Q70
PYQ

30gm \({\mathrm{HNO}}_{3}\)is added to a solution to prepare 75 % w/ w solution having density 1.25 g / mL. Volume of solution is?

Memory Based Question 28/Jan/25 Evening shift

a

32 ml

b

48 ml

c

36 ml

d

28 ml

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Q71
PYQ

The density of ' \(x\) ' \(\mathrm{M}\) solution (' \(x\) ' molar) of \(\mathrm{NaOH}\) is \(1.12\mathrm{g}{\mathrm{mL}}^{-1}\), while in molality, the concentration of the solution is \(3\mathrm{m}(3\mathrm{molal})\). Then \(x\) is
(Given : Molar mass of \(\mathrm{NaOH}\) is \(40\mathrm{g}/\mathrm{mol}\) )

[JEE Main 2024, 6 Apr (Shift 1)]

a

3.8

b

3.5

c

2.8

d

3.0

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Q72
PYQ

What is the freezing point depression constant of a solvent 50 g of which contain 1 g of non-volatile solute(M.W: 256 g/mol and depression in freezing point is 0.4 K.
Memory Based Question 28/Jan/25 Morning shift

a

\(0.372\mathrm{K}\mathrm{Kg}{\mathrm{mol}}^{-1}\)

b

\(4.213\mathrm{K}\mathrm{Kg}{\mathrm{mol}}^{-1}\)

c

\(1.86\mathrm{K}\mathrm{Kg}{\mathrm{mol}}^{-1}\)

d

\(5.12\mathrm{K}\mathrm{Kg}{\mathrm{mol}}^{-1}\)

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Q73
PYQ

A solution is made by mixing one mole of volatile liquid A with \(3\) moles of volatile liquid B. The vapour pressure of pure A is 200 mm Hg and that of the solution is \(500\) mm Hg . The vapour pressure of pure B and the least volatile component of the solution, respectively, are

[JEE Main 2025, 2 Apr (Shift 1)]

a

\(1400\mathrm{mmHg},\mathrm{A}\)

b

\(1400\mathrm{mmHg},\mathrm{B}\)

c

\(600\mathrm{mmHg},\mathrm{B}\)

d

\(600\mathrm{mmHg},\mathrm{A}\)

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Q74
PYQ

The quantity which changes with temperature is:

a

Mass percentage

b

Molality

c

Molarity

d

Mole fraction

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Q75
PYQ

Liquid A and B form an ideal solution. The vapour pressure of pure liquids A and B are \(350\) and\(750\)mm Hg respectively at the same temperature. If \({\mathrm{x}}_{\mathrm{A}}\) and \({x}_{B}\) are the mole fraction of A and B in solution while \({\mathrm{y}}_{\mathrm{A}}\) and \({y}_{B}\) are the mole fraction of A and B in vapour phase then

[JEE Main 2025, 7 Apr (Shift 2)]

a

\(\frac{{x}_{A}}{{x}_{B}}<\frac{{y}_{A}}{{y}_{B}}\)

b

\(\frac{{x}_{A}}{{x}_{B}}=\frac{{y}_{A}}{{y}_{B}}\)

c

\(\frac{{x}_{A}}{{x}_{B}}>\frac{{y}_{A}}{{y}_{B}}\)

d

\(\left({\mathrm{x}}_{\mathrm{A}}-{\mathrm{y}}_{\mathrm{A}}\right)<\left({\mathrm{x}}_{\mathrm{B}}-{\mathrm{y}}_{\mathrm{B}}\right)\)

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Q76
PYQ

The density of ' \(x\) ' \(\mathrm{M}\) solution (' \(x\) ' molar) of \(\mathrm{NaOH}\) is \(1.12\mathrm{g}{\mathrm{mL}}^{-1}\), while in molality, the concentration of the solution is \(3\mathrm{m}(3\mathrm{molal})\). Then \(x\) is
(Given : Molar mass of \(\mathrm{NaOH}\) is \(40\mathrm{g}/\mathrm{mol}\) )

[JEE Main 2024, 6 Apr (Shift 1)]

a

3.8

b

3.5

c

2.8

d

3.0

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Q77
PYQ

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

a

CHCl3 + (CH3)2CO

b

(CH3)2CO + C6H5NH2

c

(CH3)2CO + CS2

d

CHCl3 + C6H6

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Q78
PYQ

Lead storage battery contains \(38 \%\) by weight solution of \(H _2 SO _4\). 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
Given \(K _{ f }=1.8 ~K kg mol ^{-1}\)

[JEE Main 2023, 30 Jan (Shift 2)]

a

249

b

243

c

258

d

273

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Q79
PYQ

The number of units, which are used to express concentration of solutions from the following is________
Mass percent, Mole, Mole fraction, Molarity, ppm, Molality.

a

5

b

4

c

7

d

3

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Q80
PYQ

How much ethyl alcohol must be added to 1 litre of water so that the solution will freeze at –14°C?

(Kf for water = 1.86 C° /molal)

a

7.5 mol

b

8.5 mol

c

9.5 mol

d

10.5 mol

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Q81
PYQ

A \(6.50\) molal solution of \(\mathrm{KOH}(\mathrm{aq}.)\) has a density of \(1.89\mathrm{g}{\mathrm{cm}}^{-3}\). The molarity of the solution is ......... mol \({\mathrm{dm}}^{-3}\).(Round off to the Nearest Integer).

[Atomic masses: \(\mathrm{K}:39.0\mathrm{u};\mathrm{O}:16.0\mathrm{u};\mathrm{H}:1.0\mathrm{u}\) ]

[JEE Main 2021, 16 Mar (Shift 1)]

a

7

b

9

c

6

d

8

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Q82
PYQ

The molality of a \(10 \%( V / V )\) solution of di-bromine solution in \(CCl _4\) (carbon tetrachloride) is ' \(x\) '. \(x =\)________ \(\times 10^{-2} m\). (Nearest Integer)
[Given: molar mass of \(Br _2= 160 g mol ^{-1}\)
atomic mass of \(C =12 ~g mol ^{-1}\)
atomic mass of \(Cl =35.5 ~g mol ^{-1}\)
density of dibromine \(3.2 ~g cm ^{-3}\)
density of \(\left.CCl _4=1.6 ~g cm ^{-3}\right]\)

[JEE Main 2023, 1 Feb (Shift 2)]

a

140

b

139

c

138

d

141

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Q83
PYQ

A solution is prepared by adding \(2 g\) of " \(X\) " in 1 mole of water. Mass percent of " \(X\) " in the solution is

[JEE Main 2023, 11 Apr (Shift 2)]

a

\(20 \%\)

b

\(5 \%\)

c

\(2 \%\)

d

\(10 \%\)

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Q84
PYQ

A solution is prepared by adding \(2 g\) of " \(X\) " in 1 mole of water. Mass percent of " \(X\) " in the solution is

a

\(20 \%\)

b

\(5 \%\)

c

\(2 \%\)

d

\(10 \%\)

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Q85
PYQ

If \( 8 \mathrm{~g} \) of a non-electrolyte solute is dissolved in \( 114 \mathrm{~g} \) of \( \mathrm{n} \)-octane to reduce its vapour pressure to \( 80 \% \), the molar mass ( \(\mathrm{in}\) \( \mathrm{g} \mathrm{mol}^{-1} \) ) of the solute is [Given that molar mass of \( \mathrm{n} \)-octane is \( 114 \mathrm{~g} \mathrm{~mol}^{-1} \) ]

[Re-NEET 2020]

a

\( 60 \)

b

\( 80 \)

c

\( 20 \)

d

\( 40 \)

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Q86
PYQ

If the degree of dissociation of aqueous solution of weak monobasic acid is determined to be 0.3 , then the observed freezing point will be_______\(\%\) higher than the expected/ theoretical freezing point. (Nearest Integer)

[JEE Main 2023, 10 Apr (Shift 1)]

a

30

b

45

c

50

d

70

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Q87
PYQ

Mass of Urea \(\left( NH _2 CONH _2\right)\) 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 \(\mathrm{N},\mathrm{C},\mathrm{O}\mathrm{and}\mathrm{H}\) are \(14,12,16,1\mathrm{g}/\mathrm{mol}\) respectively)

[JEE Main 2023, 6 Apr (Shift 1)]

a

1111

b

1220

c

1450

d

1890

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Q88
PYQ

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

Given : Vapour pressure of water at \(38^{\circ} C\) is \(50 ~mmHg\)

[JEE Main 2023, 12 Apr (Shift 1)]

a

48

b

52

c

56

d

60

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Q89
PYQ

\(10.30 \mathrm{~mg}\) of \(\mathrm{O}_2\) dissolved into a liter of sea water of density \(1.03 \mathrm{~g} / \mathrm{mL}\). The concentration of \(\mathrm{O}_2\) in ppm is...........

a

10 ppm

b

20 ppm

c

40 ppm

d

29 ppm

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Q90
PYQ

\( 6.023 \times 10^{22} \) molecules are present in \( 10 \mathrm{~g} \) of a substance X. The molarity of a solution containing \( 5 \mathrm{~g} \) of substance X in \( 2 \mathrm{~L} \) solution is ____\( \times 10^{-3} \) M

[JEE Main 2020, 3 Sep (Shift 2)]

a

25

b

250

c

30

d

40

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Q91
PYQ

An open beaker of water in equilibrium with water vapour is in a sealed container. When a few grams of glucose are added to the beaker of water, the rate at which water molecules

[JEE Main 2020, 2 Sep (Shift 1)]

a

leaves the solution increases

b

leaves the vapour increases

c

leaves the vapour decreases

d

leaves the solution decreases

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Q92
PYQ

Henry's constant (in kbar) for four gases \(\alpha, \beta, \gamma\) and \(\delta\) in water at \(298 K\) is given below:

\[\begin{array}{c|c|c|c|c} & \alpha & \beta & \gamma & \delta \\\hline K _{ H } & 50 & 2 & 2 \times 10^{-5} & 0.5\end{array}\]

(density of water \(=10^3 kg m ^{-3}\) at \(298 K\))

Choose the correct statements

(A) \(\alpha\) has the highest solubility in water at a given pressure

(B) Solubility of \(\gamma\) at 308 K is lower than at 290 K

(C) The pressure of \(\delta\) a 55.5 molal solution of is 250 bar

(D) The pressure of a 55.5 molal solution of \(\gamma\) is 1 bar

[JEE Main 2020, 3 Sep (Shift 1)]

a

Both A and B

b

Both B and C

c

Both A and C

d

Both B and D

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Q93
PYQ

The freezing point of equimolal aqueous solutions will be highest for

a

\( \mathrm{C}_{6} \mathrm{H}_{5} \mathrm{NH}_{3} \mathrm{Cl} \) (aniline hydrochloride)

b

\( \mathrm{Ca}\left(\mathrm{NO}_{3}\right)_{2} \)

c

\( \mathrm{La}\left(\mathrm{NO}_{3}\right)_{3} \)

d

\( \mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6} \) (glucose)

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Q94
PYQ

The following solutions were prepared by dissolving \( 10 \mathrm{~g} \) of glucose \( \left(\mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6}\right) \) in \( 250 \mathrm{~ml} \) of water \( \left(\mathrm{P}_{1}\right), 10 \mathrm{~g} \) of urea \( \left(\mathrm{CH}_{4}\mathrm{~N}_{2} \mathrm{O}\right) \) in \( 250 \mathrm{~ml} \) of water \( \left(\mathrm{P}_{2}\right) \) and \( 10 \mathrm{~g} \) of sucrose \( \left(\mathrm{C}_{12} \mathrm{H}_{22} \mathrm{O}_{11}\right) \) in \( 250 \mathrm{~ml} \) of water \( \left(\mathrm{P}_{3}\right) \). The right option for the decreasing order of osmotic pressure of these solutions is

[NEET 2021]

a

\( \mathrm{P}_{1}>\mathrm{P}_{2}>\mathrm{P}_{3} \)

b

\( \mathrm{P}_{2}>\mathrm{P}_{3}>\mathrm{P}_{1} \)

c

\( \mathrm{P}_{3}>\mathrm{P}_{1}>\mathrm{P}_{2} \)

d

\( \mathrm{P}_{2}>\mathrm{P}_{1}>\mathrm{P}_{3} \)

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Q95
PYQ

The freezing point depression constant \( \left(\mathrm{K}_{f}\right) \) of benzene is \( 5.12 \) \( \mathrm{K} \mathrm{kg} \mathrm{mol}{ }^{-1} \). The freezing point depression for the solution of molality \( 0.078 \mathrm{~m} \) containing a non-electrolyte solute in benzene is (rounded off upto two decimal places) :

[NEET 2020]

a

\( 0.80 \mathrm{~K} \)

b

\( 0.40 \mathrm{~K} \)

c

\( 0.60 \mathrm{~K} \)

d

\( 0.20 \mathrm{~K} \)

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Q96
PYQ

\(50 ~mL\) of 0.2 molal urea solution (density \(=1.012 ~g mL ^{-1}\) at \(300 K\) ) is mixed with \(250 ~mL\) of a solution containing \(0.06~g\) of urea. Both the solutions were prepared in the same solvent. The osmotic pressure (in Torr) of the resulting solution at \(300 K\) is______
[Use : Molar mass of urea \(=60 ~g mol ^{-1}\); gas constant, \(R =62 ~L Torr K ^{-1} mol ^{-1}\); Assume, \(\left.\Delta_{\text {mix }} H =0, \Delta_{\text {mix }} V =0\right]\)

a

682

b

782

c

582

d

482

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Q97
PYQ

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 \(CH _2 O\). The molecular mass of \(A\) is________g. (Nearest Integer)

[JEE Main 2023, 13 Apr (Shift 1)]

a

240

b

340

c

120

d

150

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Q98
PYQ

Which one of the following \( 0.06 \mathrm{~M} \) aqueous solutions has lowest freezing point?

[JEE Main 2021, 22 Jul (Shift 2)]

a

\( \mathrm{Kl} \)

b

\( \mathrm{Al}_{2}\left(\mathrm{SO}_{4}\right)_{3} \)

c

\( \mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6} \)

d

\( \mathrm{K}_{2} \mathrm{SO}_{4} \)

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Q99
PYQ

If 80 g of copper sulphate CuSO4⋅5H2O is dissolved in deionised water to make 5 L of solution. The concentration of the copper sulphate solution is \(\mathrm{x}\times {10}^{-3}\mathrm{mol}/\mathrm{L}\). The value of x is [Atomic masses Cu : 63.54u, S:32u, O:16u, H:1u]

[JEE Main 2021, 1 Sep (Shift 2)]

a

64

b

72

c

78

d

84

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Q100
PYQ

\(4.5 g\) of compound \(A(M W=90)\) was used to make \(250 ~mL\) of its aqueous solution. The molarity of the solution in \(M\) is \(x \times 10^{-1}\). The value of \(x\) is (Rounded off to the nearest integer)

[JEE Main 2021, 24 Feb (Shift 1)]

a

2

b

1

c

3

d

4

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Q101
PYQ

Liquids A and B form an ideal solution in the entire composition range. At 350 K , the vapor pressures of pure A and pure B are \(7\times {10}^{3}\mathrm{Pa}\mathrm{and}12\times {10}^{3}\mathrm{Pa}\), respectively. The composition of the vapour is in equilibrium with a solution containing 40 mole percent of at this temperature is:

a

\({\mathrm{x}}_{\mathrm{A}}=0.37;{\mathrm{x}}_{\mathrm{B}}=0.63\)

b

\({\mathrm{x}}_{\mathrm{A}}=0.28;{\mathrm{x}}_{\mathrm{B}}=0.72\)

c

\({\mathrm{x}}_{\mathrm{A}}=0.4;{\mathrm{x}}_{\mathrm{B}}=0.6\)

d

\({\mathrm{x}}_{\mathrm{A}}=0.76;{\mathrm{x}}_{\mathrm{B}}=0.24\)

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Q102
PYQ

A solute A dimerizes in water. The boiling point of a 2 molal solution of \( \mathrm{A} \) is \( 100.52^{\circ} \mathrm{C} \). The percentage association of \( A \) is ____ (Round off to the Nearest Integer). [Use: \( \mathrm{K}_{\mathrm{b}} \) for water \( =0.52 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}^{-1} \)

Boiling point of water \( \left.=100^{\circ} \mathrm{C}\right] \)

[JEE Main 2021, 18 Mar (Shift 2)]

a

100

b

200

c

300

d

400

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Q103
PYQ

\(\begin{array}{|c|c|c|}\hline \begin{array}{l}\text { Match List-I with List-II. } \\\text { List-I }\end{array} & & \begin{array}{l}\text { List-II }\end{array} \hline \text { (A) Van't Hoff Factor, i } & \text { (I) } & \text { Cryoscopic constant } \hline \text { (B) } k _{ f } & \text { (II) } & \text { Isotonic solutions } \hline \text { C) Solutions with same } & \text { (III) } & \text { Normal molar mass } \hline & & \overline{\text { Abnormal molar mass }} \hline \text { D) Azeotropes } & \text { (IV) } & \begin{array}{l}\text { Solutions with same } \\\text { composition of vapour } \\\text { above it }\end{array} \hline\end{array}\)

a

\(\text { (A)-(III), (B)-(I), (C)-(II), (D)-(IV) }\)

b

\(\text { (A)-(III), (B)-(II), (C)-(I), (D)-(IV) }\)

c

\(\text { (A)-(III), (B)-(I), (C)-(IV), (D)-(II) }\)

d

\(\text { (A)-(I), (B)-(III), (C)-(II), (D)-(IV) }\)

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Q104
PYQ

If the concentration of glucose \(\left({\mathrm{C}}_{6}{\mathrm{H}}_{12}{\mathrm{O}}_{6}\right)\) in blood is 0.72 gL–1, the molarity of glucose in blood is_______ ×10–3M. (Nearest Integer)

(Given: Atomic mass of C = 12u, H = 1u, O = 16u)

[JEE Main 2021, 22 Jul (Shift 2)]

a

4

b

3

c

5

d

1

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Q105
PYQ

\(100 ~mL\) of \(Na _3 PO _4\) solution contains \(3.45 g\) of sodium. The molarity of the solution is__________ \(\times 10^{-2} mol L ^{-1}\), (Nearest Integer)
[Atomic Masses - \(Na : 23.0 ~u , O : 16.0 ~u , P : 31.0 ~u\) ]

[JEE Main 2021, 26 Aug (Shift 2)]

a

20

b

40

c

30

d

50

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Q106
PYQ

\( 224 \mathrm{~mL} \) of \( \mathrm{SO}_{2(\mathrm{~g})} \) at \( 298 \mathrm{~K} \) and \( 1 \mathrm{~atm} \) is passed through \( 100 \mathrm{~mL} \) of \( 0.1 \mathrm{~M} \mathrm{~NaOH} \) solution. The non-volatile solute produced is dissolved in \( 36 \mathrm{~g} \) of water. The lowering of vapour pressure of solution (assuming the solution is dilute) \( \left(\mathrm{P}_{\left(\mathrm{H}_{2} \mathrm{O}\right)}^{\mathrm{O}}=24 \mathrm{~mm}\right. \) of \( \left.\mathrm{Hg}\right) \) is \( \mathrm{x} \times 10^{-2} \mathrm{~mm} \) of \( \mathrm{Hg} \), the value of \( \mathrm{x} \) is ...... (Integer answer)

[JEE Main 2021, 26 Feb (Shift 1)]

a

24

b

30

c

36

d

42

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Q107
PYQ

A 1 molal \( \mathrm{K}_{4} \mathrm{Fe}(\mathrm{CN})_{6} \) solution has a degree of dissociation of 0.4 . Its boiling point is equal to that of another solution which contains 18.1 weight percent of a non electrolytic solute \( \mathrm{A} \). The molar mass of \( \mathrm{A} \) is ___u. (Round off to the Nearest Integer). [Density of water \( =1.0 \mathrm{~g} \mathrm{~cm}^{-3} \) ]

[JEE Main 2021, 17 Mar (Shift 2)]

a

85

b

80

c

75

d

70

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Q108
PYQ

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 \(m\) times the boiling point elevation constant of \(Y\). The value of \(m\) is_______(Nearest Integer)

[JEE Main 2023, 8 Apr (Shift 2)]

a

8

b

10

c

12

d

14

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Q109
PYQ

The molarity of the solution prepared by dissolving \( 6.3 \mathrm{~g} \) of oxalic acid \( \left(\mathrm{H}_{2} \mathrm{C}_{2} \mathrm{O}_{4} \cdot 2 \mathrm{H}_{2} \mathrm{O}\right) \) in \( 250 \mathrm{~mL} \) of water in \( \mathrm{molL}^{-1} \) is \( \mathrm{x} \times 10^{-2} \). The value of \( \mathrm{x} \) is (Nearest integer) [Atomic mass: \( \mathrm{H}: 1.0, \mathrm{C}: 12.0,0: 16.0 \) ]

[JEE Main 2021, 31 Aug (Shift 1)]

a

20

b

30

c

40

d

50

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Q110
PYQ

The water having more dissolved \({\mathrm{O}}_{2}\) is:

[JEE Main 2021, 22 Jul (Shift 2)]

a

Water at \(80^\circ \mathrm{C}\)

b

boiling water

c

polluted water

d

water at \(4^\circ \mathrm{C}\)

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Q111
PYQ

\( \mathrm{AB}_{2} \) is \( 10 \% \) dissociated in water to \( \mathrm{A}^{2+} \) and \( \mathrm{B}^{-} \). The boiling point of a 10.0 molal aqueous solution of \( \mathrm{AB}_{2} \) is _____\( { }^{\circ} \mathrm{C} \). (Round off to the Nearest Integer)

[Given: Molal elevation constant of water, \({\mathrm{K}}_{\mathrm{b}}=0.5\mathrm{K}{\mathrm{Kgmol}}^{-1}\), boiling point of pure water \( \left.=100^{\circ} \mathrm{C}\right] \)

[JEE Main 2021, 16 Mar (Shift 1)]

a

106

b

112

c

118

d

124

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Q112
PYQ

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

Given : \(\mathrm{R}=0.083 \mathrm{~L} \mathrm{bar} \mathrm{K}^{-1} \mathrm{~mol}^{-1}\)

[JEE Main 2023, 10 Apr (Shift 2)]

a

40535

b

41020

c

51024

d

26743

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Q113
PYQ

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 \(180 ~g mol ^{-1}\)

[JEE Main 2023, 11 Apr (Shift 2)]

a

\(4.69 g\)

b

\(3.59 g\)

c

\(2.59 g\)

d

\(3.69 g\)

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Q114
PYQ

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R)

Assertion A: \(3.1500 ~g\) of hydrated oxalic acid dissolved in water to make \(250.0 ~mL\) solution will result in \(0.1 ~M\) oxalic acid solution.

Reason R: Molar mass of hydrated oxalic acid is \(126 ~g mol ^{-1}\).

In the light of the above statements, choose the correct answer from the options given below

[JEE Main 2023, 10 Apr (Shift 2)]

a

Both (A) and (R) are true but (R) is not explanation of (A).

b

(A) is false but (R) is true.

c

(A) is true but (R) is false.

d

Both (A) and (R) are true and (R) is the correct explanation of (A).

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Q115
PYQ

The number of units, which are used to express concentration of solutions from the following is
Mass percent, Mole, Mole fraction, Molarity, ppm, Molality

[JEE Main 2023, 24 Jan (Shift 2)]

a

5

b

4

c

2

d

3

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Q116
PYQ

\( 1.22 \mathrm{~g} \) of an organic acid is separately dissolved in \( 100 \mathrm{~g} \) of benzene \( \left(\mathrm{K}_{\mathrm{b}}=2.6 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}^{-1}\right) \) and \( 100 \mathrm{~g} \) of acetone \( \left(\mathrm{K}_{\mathrm{b}}=1.7 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}^{-1}\right) \). The acid is known to dimerize in benzene but remain as a monomer in acetone. The boiling point of the solution in acetone increases by \( 0.17^{\circ} \mathrm{C} \). The increase in boiling point of solution in benzene in \( { }^{\circ} \mathrm{C} \) is \( \mathrm{x} \times 10^{-2} \). The value of \( \mathrm{x} \) is ........ (Nearest integer) [Atomic mass: \( \mathrm{C}=12.0, \mathrm{H}=1.0, \mathrm{O}=16.0 \) )

a

13

b

20

c

26

d

32

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Q117
PYQ

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 ...................g/mol (Nearest Integer)
(Given, water boils at \(373\mathrm{K}\) and \({\mathrm{K}}_{\mathrm{b}}\) for water \(0.52\mathrm{K}\mathrm{Kg}{\mathrm{mol}}^{-1}\))

a

100

b

200

c

300

d

400

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Q118
PYQ

Sea water contains 29.25% NaCl and 19% MgCl2 by weight of solution. The normal boiling point of the sea water is (in °C) (Nearest Integer) Assume 100 % ionization for both NaCl and MgCl2
Given: \(K _{ b }\left( H _2 O \right)=0.52 ~K kg mol ^{-1}\)
Molar mass of NaCl and MgCl2 is 58.5 and 95 g mol–1 respectively

a

116

b

118

c

120

d

122

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Q119
PYQ

\(20 \%\) 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__________ \(\times 10^{-3}\) \({}^{\mathrm{o}}\mathrm{C}\). Atomic mass of \(C , H\) and \(O\) are \(12,1,16\mathrm{amu}\)
[Given: Molal depression constant and density of water are \(1.86 ~K kg mol ^{-1}\) and \(1 ~gcm ^{-3}\) respectively]

[JEE Main 2023, 1 Feb (Shift 2)]

a

372

b

380

c

388

d

396

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Q120
PYQ

The enthalpy change for the adsorption process and micelle formation respectively are

[JEE Main 2023, 10 Apr (Shift 1)]

a

\(\Delta {H}_{\text{ads }}<0\mathrm{and}\Delta {H}_{\text{mix }}>0\)

b

\(\Delta {H}_{\text{ads }}<0\mathrm{and}\Delta {H}_{\text{mix }}<0\)

c

\(\Delta {H}_{ads}>0\mathrm{and}\Delta {H}_{\text{mix }}<0\)

d

\(\Delta {H}_{ads}>0\mathrm{and}\Delta {H}_{\text{mix }}>0\)

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Q121
PYQ

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 the freezing point

[JEE Main 2023, 24 Jan (Shift 1)]

a

\(\text {(A) and (D) only }\)

b

\(\text {(B) and (C) only }\)

c

\(\text {(A) and (C) only }\)

d

\(\text {(A) only }\)

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Q122
PYQ

1 molal aqueous solution of an electrolyte \( \mathrm{A}_{2} \mathrm{B}_{3} \) is \( 60 \% \) ionised. The boiling point of the solution at \( 1 \mathrm{~atm} \) is ....... K. (Rounded-off to the nearest integer) [Given: \( \mathrm{K}_{\mathrm{b}} \) for \( \left(\mathrm{H}_{2} \mathrm{O}\right)=0.52 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}^{-1} \) ]

[JEE Main 2021, 25 Feb (Shift 1)]

a

375

b

390

c

415

d

420

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Q123
PYQ

\(0.004 ~M ~K _2 SO _4\) solution is isotonic with \(0.01 ~M\) glucose solution. Percentage dissociation of \(K _2 SO _4\) is _________ (Nearest Integer)

[JEE Main 2023, 11 Apr (Shift 1)]

a

75

b

80

c

85

d

90

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Q124
PYQ

The total pressure of a mixture of non-reacting gases \(X (0.6 g )\) and \(Y (0.45 g )\) in a vessel is \(740 mm\) of \(Hg\). The partial pressure of the gas \(X\) is______ \(mm\) of \(Hg\). (Nearest Integer)
(Given : molar mass \(X =20\) and \(Y =45 g mol ^{-1}\) )

[JEE Main 2023, 31 Jan (Shift 1)]

a

555

b

444

c

333

d

222

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Q125
PYQ

Given below are two statements
Statement (I) : Molal depression constant \({\mathrm{K}}_{\mathrm{f}}\) is given by \(\frac{{M}_{1}R{T}_{f}}{\Delta {S}_{\text{fus }}}\), where symbols have their usual meaning.
Statement (II) : \({\mathrm{K}}_{\mathrm{f}}\) for benzene is less than the \({\mathrm{K}}_{\mathrm{f}}\) for water.
In the light of the above statements, choose the most appropriate answer from the options given below

[JEE Main 2025, 4 Apr (Shift 2)]

a

Statement I is incorrect but Statement II is correct

b

Both Statement I and Statement II are incorrect

c

Both Statement I and Statement II are correct

d

Statement I is correct but Statement II is incorrect

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Q126
PYQ

At \( 35^{\circ} \mathrm{C} \), the vapour pressure of \( \mathrm{CS}_{2} \) is \( 512 \mathrm{~mm} \mathrm{Hg} \) and that of acetone is \( 344 \mathrm{~mm} \mathrm{Hg} \). A solution of \( \mathrm{CS}_{2} \) in acetone has a total vapour pressure of \( 600 \mathrm{~mm} \mathrm{Hg} \). The false statement amongst the following is:

a

heat must be absorbed in order to produce the solution at \( 35^{\circ} \mathrm{C} \)

b

Raoults law is not obeyed by this system

c

a mixture of \( 100 \mathrm{~mL} \mathrm{~CS}_{2} \) and \( 100 \mathrm{~mL} \) acetone has a volume \( <200 \mathrm{~mL} \)

d

\( \mathrm{CS}_{2} \) and acetone are less attracted to each other than to themselves.

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Q127
PYQ

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. \(CaCl _2\) and \(1.5 M\) aq. \(KCl\)
(c) \(1.5 M\) aq. \(AlCl _3\) and \(2 M\) aq. \(Na _2 SO _4\)
(d) \(2.5 M\) aq. \(KCl\) and \(1 M\) aq. \(Al _2\left( SO _4\right)_3\)

[JEE Main 2023, 6 Apr (Shift 2)]

a

4

b

3

c

2

d

1

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Q128
PYQ

When \( 12.2 \mathrm{~g} \) of benzoic acid is dissolved in \( 100 \mathrm{~g} \) of water, the freezing point of solution was found to be \( -0.93^{\circ} \mathrm{C} \) \( \left(\mathrm{K}_{\mathrm{f}}\left(\mathrm{H}_{2} \mathrm{O}\right)=1.86 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}^{-1}\right) \). The number (n) of benzoic acid molecules associated (assuming 100 % association) is

[JEE Main 2021, 26 Feb (Shift 2)]

a

2

b

3

c

4

d

5

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