Question

If osmotic pressure of $0.2 \text{ M}$ aqueous glucose solution is $5 \text{ atm}$ at $300 \text{ K}$. Calculate the concentration of glucose solution having osmotic pressure $2.5 \text{ atm}$ at same temperature.

• A. $0.1 \text{ M}$
• B. $0.05 \text{ M}$
• C. $0.75 \text{ M}$
• D. $0.25 \text{ M}$

Hint:

At constant T: $\pi \propto C$

Answer 1

The Correct Option is A

Concept: \[ \pi = CRT \Rightarrow \pi \propto C \quad (\text{T constant}) \]

Step 1: Set ratio. \[ \frac{\pi_1}{\pi_2} = \frac{C_1}{C_2} \]

Step 2: Substitute values. \[ \frac{5}{2.5} = \frac{0.2}{C_2} \] \[ 2 = \frac{0.2}{C_2} \]

Step 3: Solve. \[ C_2 = \frac{0.2}{2} = 0.1 \]

Step 4: Conclusion.
Concentration = $0.1 \text{ M}$ Final Answer: Option (A)