Question

Calculate the concentration of an aqueous solution of non electrolyte at $300\text{ K}$ if its osmotic pressure is $12\text{ atm}$.
$[ \text{R} = 0.0821\text{ atm dm}^3\text{ K}^{-1}\text{ mol}^{-1} ]$

• A. $0.371\text{ M}$
• B. $0.615\text{ M}$
• C. $0.487\text{ M}$
• D. $0.726\text{ M}$

Hint:

Use $T$ in Kelvin always! (K = $^\circ$C + 273.15).

Answer 1

The Correct Option is C

Step 1: Concept Osmotic pressure ($\pi$) is given by the formula $\pi = CRT$.

Step 2: Meaning $C$ is the molar concentration, $R$ is the gas constant, and $T$ is the absolute temperature.

Step 3: Analysis $12 = C \times 0.0821 \times 300$.
$C = \frac{12}{0.0821 \times 300} = \frac{12}{24.63}$.

Step 4: Conclusion $C \approx 0.487\text{ mol/dm}^3$ (or M). Final Answer: (C)