JEE Main 2023 — Chemistry Physical Chemistry

2023integermedium

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

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

Official previous-year question

Held on 31 Jan 2023 · Verified 6 Jul 2026.

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Solution

The osmotic pressure of a non-electrolytic solution can be calculated as follows,

$\pi =\mathrm{CRT}$

$\pi$ = osmotic pressure

$C$ = molarity

$\frac{400\mathrm{Pa}}{{10}^{5}}=\frac{\frac{2.5g}{{M}_{o}}}{250/1000L}\times 0.83\frac{L-\mathrm{bar}}{K.\mathrm{mol}}\times 300K$

$\Rightarrow \frac{400\times {10}^{-5}}{(1.01325)}=[\frac{2.5\times 1000}{{M}_{o}\times 250}]0.083\times 300$

$\Rightarrow 400\times {10}^{-5}=\frac{10}{{M}_{o}}\times 0.083\times 300$

$\Rightarrow {M}_{o}=\frac{10\times 0.83\times 300}{400}\times {10}^{5}$

$\Rightarrow {M}_{o}=[\frac{10\times 0.083\times 3}{4}]\times {10}^{5}$

$\Rightarrow {M}_{o}=62250$ gram/mole

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JEE Main 2023 — Chemistry Physical Chemistry

2023integermedium

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

Official previous-year question

Held on 31 Jan 2023 · Verified 6 Jul 2026.

Did you get this right?

Solution

The osmotic pressure of a non-electrolytic solution can be calculated as follows,

$\pi =\mathrm{CRT}$

$\pi$ = osmotic pressure

$C$ = molarity

$\frac{400\mathrm{Pa}}{{10}^{5}}=\frac{\frac{2.5g}{{M}_{o}}}{250/1000L}\times 0.83\frac{L-\mathrm{bar}}{K.\mathrm{mol}}\times 300K$

$\Rightarrow \frac{400\times {10}^{-5}}{(1.01325)}=[\frac{2.5\times 1000}{{M}_{o}\times 250}]0.083\times 300$

$\Rightarrow 400\times {10}^{-5}=\frac{10}{{M}_{o}}\times 0.083\times 300$

$\Rightarrow {M}_{o}=\frac{10\times 0.83\times 300}{400}\times {10}^{5}$

$\Rightarrow {M}_{o}=[\frac{10\times 0.083\times 3}{4}]\times {10}^{5}$

$\Rightarrow {M}_{o}=62250$ gram/mole

Your note

JEE Main Physical Chemistry in other years

Keep practicing Physical Chemistry

Work through every JEE Main Physical Chemistry PYQ, year by year.

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JEE Main 2023 — Chemistry Physical Chemistry

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Solution

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JEE Main Physical Chemistry in other years

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JEE Main 2023 — Chemistry Physical Chemistry

Did you get this right?

Solution

Your note

JEE Main Physical Chemistry in other years

More JEE Main Physical Chemistry questions

Other Chemistry topics for JEE Main

Organic Chemistry

Inorganic Chemistry

Keep practicing Physical Chemistry