JEE Main 2021 — Chemistry Physical Chemistry

2021integerhard

Of the following four aqueous solutions, the total number of those solutions whose freezing point is lower than that of $0.10{\mathrm{MC}}_{2}{H}_{5}\mathrm{OH}$ is (Integer answer)

(i) $0.10M{\mathrm{Ba}}_{3}{({\mathrm{PO}}_{4})}_{2}$

(ii) $0.10M{\mathrm{Na}}_{2}{\mathrm{SO}}_{4}$

(iii) $0.10M\mathrm{KCl}$

(iv) $0.10M{\mathrm{Li}}_{3}{\mathrm{PO}}_{4}$

Official previous-year question

Held on 26 Aug 2021 · Verified 6 Jul 2026.

Did you get this right?

Solution

${\Delta T}_{f}={\mathrm{ik}}_{f}m$

As $m$ is the same for all solutions so ${\Delta T}_{f}$ depends on Van't Hoff factor (i). Greater is i small is freezing point.

$\begin{matrix}\text{ Compound } & \text{ i } \\ {C}_{2}{H}_{5}\mathrm{OH} & 1 \\ {\mathrm{Ba}}_{3}{({\mathrm{PO}}_{4})}_{2} & 5 \\ {\mathrm{Na}}_{2}{\mathrm{SO}}_{4} & 3 \\ \mathrm{KCl} & 2 \\ {\mathrm{Li}}_{3}{\mathrm{PO}}_{4} & 4\end{matrix}$

So the given solutions have a lower freezing point than ethanol.

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JEE Main Physical Chemistry in other years

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JEE Main 2021 — Chemistry Physical Chemistry

2021integerhard

Of the following four aqueous solutions, the total number of those solutions whose freezing point is lower than that of $0.10{\mathrm{MC}}_{2}{H}_{5}\mathrm{OH}$ is (Integer answer)

(i) $0.10M{\mathrm{Ba}}_{3}{({\mathrm{PO}}_{4})}_{2}$

(ii) $0.10M{\mathrm{Na}}_{2}{\mathrm{SO}}_{4}$

(iii) $0.10M\mathrm{KCl}$

(iv) $0.10M{\mathrm{Li}}_{3}{\mathrm{PO}}_{4}$

Official previous-year question

Held on 26 Aug 2021 · Verified 6 Jul 2026.

Did you get this right?

Solution

${\Delta T}_{f}={\mathrm{ik}}_{f}m$

As $m$ is the same for all solutions so ${\Delta T}_{f}$ depends on Van't Hoff factor (i). Greater is i small is freezing point.

So the given solutions have a lower freezing point than ethanol.

Your note

JEE Main Physical Chemistry in other years

Keep practicing Physical Chemistry

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

Browse all Chemistry topics

JEE Main 2021 — 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

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Keep practicing Physical Chemistry

JEE Main 2021 — 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