Question

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

$\begin{array}{ccccc}& \mathrm{\alpha }& \mathrm{\beta }& \mathrm{\gamma }& \mathrm{\delta }\\ {\mathrm{K}}_{\mathrm{H}}& 50& 2& 2\times {10}^{-5}& 0.5\end{array}$

(density of water $={10}^3 \mathrm{k} {\mathrm{gm}}^{-3}$ at $298 \mathrm{K}$ ) This table implies that :

JEE Main 2020 (03 Sep Shift 1)

Options

• A: $\alpha$ has the highest solubility in water at a given pressure
• B: solubility of $\gamma$ at $308K$ is lower than at $298K$
• C: The pressure of a $55.5$ molal solution of $\mathrm{\delta }$ is $250$ bar
• D: The pressure of $55.5$ molal solution of $\mathrm{\gamma }$ is $1 \mathrm{bar}$.

Question

At $35{ }^{\mathrm{o}}\mathrm{C},$ the vapour pressure of $\mathrm{C}{\mathrm{S}}_2,$ is $512\mathrm{}\mathrm{m}\mathrm{m}$ Hg and that of acetone is $144 \mathrm{m}\mathrm{m}\mathrm{H}\mathrm{g}.$ A solution of $\mathrm{C}{\mathrm{S}}_2$ in acetone has a total vapour pressure of $\mathrm{600 }\mathrm{}\mathrm{m}\mathrm{m}\mathrm{}\mathrm{H}\mathrm{g}$ . The false statement amongst the following is:

JEE Main 2020 (07 Jan Shift 1)

Options

• A: Raoult's law is not obeyed by this system
• B: a mixture of $100\mathrm{}\mathrm{m}\mathrm{L}\mathrm{}{\mathrm{C}\mathrm{S}}_2$ and $100\mathrm{}\mathrm{m}\mathrm{L}$ acetone has a volume $<\mathrm{}200\mathrm{}\mathrm{m}\mathrm{L}$
• C: ${\mathrm{C}\mathrm{S}}_2$ and acetone are less attracted to each other than to themselves
• D: heat must be absorbed in order to produce the solution at ${35}^{\mathrm{o}}\mathrm{C}$

Question

The elevation of boiling point of $0.10\mathrm{m}$ aqueous ${\mathrm{CrCl}}_3.{\mathrm{xNH}}_3$ solution is two times that of $0.05 \mathrm{m}$ aqueous ${\mathrm{CaCl}}_2$ solution. The value of $x$ is $\dots \dots \dots \dots ..$
[Assume $100\%$ ionisation of the complex and ${\mathrm{CaCl}}_2,$ coordination number of $\mathrm{Cr}$ as $6,$ and that all ${\mathrm{NH}}_3$ molecules are present inside the coordination sphere]

JEE Main 2020 (06 Sep Shift 1)

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Question

A cylinder containing an ideal gas ( $0.1\mathrm{}\mathrm{m}\mathrm{o}\mathrm{l}$ of $1.0\mathrm{}\mathrm{d}{\mathrm{m}}^3$ ) is in thermal equilibrium with a large volume of $0.5$ molal aqueous solution of ethylene glycol at its freezing point. If the stoppers ${\mathrm{S}}_1$ and ${\mathrm{S}}_2$ (as shown in the figure) are suddenly withdrawn, the volume of the gas in litres after equilibrium is achieved will be _____________.
(Given, ${\mathrm{K}}_{\mathrm{f}}\left(\mathrm{w}\mathrm{a}\mathrm{t}\mathrm{e}\mathrm{r}\right)=2.0\mathrm{K}\mathrm{k}\mathrm{g}\mathrm{m}\mathrm{o}{\mathrm{l}}^{-1},\left.\mathrm{R}=0.08\mathrm{d}{\mathrm{m}}^3\mathrm{a}\mathrm{t}\mathrm{m}\mathrm{}{\mathrm{K}}^{-1}\mathrm{m}\mathrm{o}{\mathrm{l}}^{-1}\right)$

JEE Main 2020 (09 Jan Shift 2)

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Question

$2$ molal solution of a weak acid $\mathrm{HA}$ has a freezing point of $3.885°\mathrm{C}.$ The degree of dissociation of this acid is ______$\times {10}^{-3}.$ (Round off to the Nearest Integer). $[$Given : Molal depression constant of water $=1.85 \mathrm{K} \mathrm{kg}{ \mathrm{mol}}^{-1}$ Freezing point of pure water$\left.=0°\mathrm{C}\right]$

JEE Main 2021 (18 Mar Shift 1)

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Question

${\mathrm{CO}}_2$ gas is bubbled through water during a soft drink manufacturing process at $298 \mathrm{K}$. If ${\mathrm{CO}}_2$ exerts a partial pressure of $0.835 \mathrm{bar}$ then $\mathrm{x} \mathrm{m} \mathrm{mol}$ of ${\mathrm{CO}}_2$ would dissolve in $0.9 \mathrm{L}$ of water. The value of $\mathrm{x}$ is _______. (Nearest integer)

(Henry's law constant for ${\mathrm{CO}}_2$ at $298 \mathrm{K}$ is $1.67\times {10}^3 \mathrm{bar}$)

JEE Main 2021 (25 Jul Shift 1)

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Question

$1.80 \mathrm{g}$ of solute A was dissolved in $62.5 {\mathrm{cm}}^3$ of ethanol and freezing point of the solution was found to be $155.1 \mathrm{K}$. The molar mass of solute $\mathrm{A}$ is ${\mathrm{gmol}}^{-1}$. [Given: Freezing point of ethanol is $156.0 \mathrm{K}$. Density of ethanol is $0.80 \mathrm{g} {\mathrm{cm}}^{-3}$. Freezing point depression constant of ethanol is $2.00 \mathrm{K} \mathrm{kg} {\mathrm{mol}}^{-1}$]

JEE Main 2022 (29 Jul Shift 2)

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Question

Some amount of dichloromethane $\left({\mathrm{CH}}_2{\mathrm{Cl}}_2\right)$ is added to $671.141\mathrm{mL}$ of chloroform $\left({\mathrm{CHCl}}_3\right)$ to prepare $2.6\times {10}^{-3}\mathrm{M}$ solution of ${\mathrm{CH}}_2{\mathrm{Cl}}_2\left(\mathrm{DCM}\right)$. The concentration of $\mathrm{DCM}$ is _____ ppm (by mass).

Given: Atomic mass : $\mathrm{C}=12;\mathrm{H}:1;\mathrm{Cl}=35.5$ density of ${\mathrm{CHCl}}_3=1.49\mathrm{g} {\mathrm{cm}}^{-3}$

JEE Main 2023 (30 Jan Shift 1)

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Question

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

JEE Main 2024 (04 Apr Shift 1)

Options

• A: 2
• B: 20
• C: 4
• D: 0.2

Question

\(2.7 \mathrm{~kg}\) of each of water and acetic acid are mixed. The freezing point of the solution will be \(-x^{\circ} \mathrm{C}\). Consider the acetic acid does not dimerise in water, nor dissociates in water. \(x=\) ______ (nearest integer) [Given: Molar mass of water \(=18 \mathrm{~g} \mathrm{~mol}^{-1}\), acetic acid \(=60 \mathrm{~g} \mathrm{~mol}^{-1}\) \(\mathrm{K}_{\mathrm{f}} \mathrm{H}_2 \mathrm{O}: 1.86 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}^{-1}\) \(\mathrm{K}_{\mathrm{f}}\) acetic acid: \(3.90 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}^{-1}\) freezing point: \(\mathrm{H}_2 \mathrm{O}=273 \mathrm{~K}\), acetic acid \(=290 \mathrm{~K}\)]

JEE Main 2024 (04 Apr Shift 2)

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Question

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 temperature is _______ \(\times 10^{-2}\) (nearest integer)

JEE Main 2024 (09 Apr Shift 2)

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Question

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

JEE Main 2024 (30 Jan Shift 1)

Options

• A: Increases
• B: Remains unchanged 
• C: First decreases and then increases
• D: Decreases

Question

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

JEE Main 2024 (31 Jan Shift 1)

Options

• A: $({\mathrm{CH}}_3{)}_2\mathrm{CO}+{\mathrm{C}}_6{\mathrm{H}}_5{\mathrm{NH}}_2$
• B: ${\mathrm{CHCl}}_3+{\mathrm{C}}_6{\mathrm{H}}_6$
• C: ${\mathrm{CHCl}}_3+({\mathrm{CH}}_3{)}_2\mathrm{CO}$
• D: $({\mathrm{CH}}_3{)}_2\mathrm{CO}+{\mathrm{CS}}_2$

Question

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

JEE Main 2024 (29 Jan Shift 1)

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Question

Given below are two statements: Statement I : Gallium is used in the manufacturing of thermometers. Statement II : A thermometer containing gallium is useful for measuring the freezing point \((256 \mathrm{~K})\) of brine solution. In the light of the above statements, choose the correct answer from the options given below :

JEE Main 2024 (06 Apr Shift 1)

Options

• A: Both Statement I and Statement II are true
• B: Statement I is false but Statement II is true
• C: Both Statement I and Statement II are false
• D: Statement I is true but Statement II is false