JEE Main 2023 — Chemistry Physical Chemistry

2023integerhard

Some amount of dichloromethane $({\mathrm{CH}}_{2}{\mathrm{Cl}}_{2})$ is added to $671.141\mathrm{mL}$ of chloroform $({\mathrm{CHCl}}_{3})$ to prepare $2.6\times {10}^{-3}M$ solution of ${\mathrm{CH}}_{2}{\mathrm{Cl}}_{2}(\mathrm{DCM})$ . The concentration of $\mathrm{DCM}$ is _____ ppm (by mass).

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

Official previous-year question

Held on 30 Jan 2023 · Verified 6 Jul 2026.

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Solution

$\mathrm{Molarity}=\frac{\mathrm{mole}}{\mathrm{Volume}\mathrm{in}L }=\frac{\mathrm{mass}/\mathrm{Molar}\mathrm{mass}}{\mathrm{Volume}\mathrm{in}L}$

$2.6\times {10}^{-3}=\frac{x/85}{0.67141}$

$x=0.148g$

The number of ppm $=\frac{\mathrm{mass}\mathrm{of}\mathrm{solute}}{\mathrm{mass}\mathrm{of}\mathrm{solution}}\times {10}^{6}$

Mass of solution = density of solution $\times$ Volume of solution

$\mathrm{DCM}$ in ppm $=\frac{0.148}{1.49\times 671.141}\times {10}^{6}$

$=148\mathrm{ppm}$ .

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JEE Main 2023 — Chemistry Physical Chemistry

2023integerhard

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

Official previous-year question

Held on 30 Jan 2023 · Verified 6 Jul 2026.

Did you get this right?

Solution

$\mathrm{Molarity}=\frac{\mathrm{mole}}{\mathrm{Volume}\mathrm{in}L }=\frac{\mathrm{mass}/\mathrm{Molar}\mathrm{mass}}{\mathrm{Volume}\mathrm{in}L}$

$2.6\times {10}^{-3}=\frac{x/85}{0.67141}$

$x=0.148g$

The number of ppm $=\frac{\mathrm{mass}\mathrm{of}\mathrm{solute}}{\mathrm{mass}\mathrm{of}\mathrm{solution}}\times {10}^{6}$

Mass of solution = density of solution $\times$ Volume of solution

$\mathrm{DCM}$ in ppm $=\frac{0.148}{1.49\times 671.141}\times {10}^{6}$

$=148\mathrm{ppm}$ .

Your note

JEE Main Physical Chemistry in other years

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JEE Main 2023 — Chemistry Physical Chemistry

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JEE Main 2023 — Chemistry Physical Chemistry

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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

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