For a substance at a given temperature, the osmotic pressure of its concentrated solution
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → is higher than that of dilute solution
Osmotic pressure is a colligative property: it depends on the number of solute particles per unit volume. For a dilute solution it is given by
\( \pi = CRT \)
where C is the molar concentration. At a given temperature, R and T are fixed, so π is proportional to C. A concentrated solution of the same substance has a larger C, so its osmotic pressure is higher.
Why the other options are incorrect
Option (1) is same as that of dilute solution — Incorrect. π would be the same only if the concentrations were the same.
Option (2) is lower than that of dilute solution — Incorrect. This would need π to fall as C rises, the reverse of π = CRT.
Option (4) cannot be compared with osmotic pressure of dilute solution — Incorrect. Both are solutions of the same substance at the same temperature, so π = CRT compares them directly.
NCERT (2026-27 edition):
Osmosis and Osmotic Pressure – …
Note: The same/similar question has been asked in different years by NTA as per the details given below:
| 2026 | 2025 | 2024 | 2023 | 2022 |
|---|---|---|---|---|
| – | 29-05 S2 | – | 25-05 S3 | – |