Osmotic pressure of a solution is 0.0821 atm at a temperature of 300 K. The concentration in moles/litre will be:

0.3 × l0^–2

The correct answer is option 3. \(0.3 \times 10^{-2}\).

To find the concentration of the solution in moles per liter (Molarity), we can use the formula relating osmotic pressure (\(\pi\)), molarity (\(M\)), the ideal gas constant (\(R\)), and temperature (\(T\)):

\(\pi = MRT\)

Given:

Osmotic pressure (\(\pi\)) = 0.0821 atm

Temperature (\(T\)) = 300 K

Ideal gas constant (\(R\)) = 0.0821 L·atm·K\(^{-1}\)·mol\(^{-1}\)

We need to solve for \(M\), the concentration in moles per liter.

1. Convert the temperature to Kelvin: \( T = 300 \) K

2. Substitute the given values into the formula:

\(0.0821 = M \cdot 0.0821 \cdot 300\)

3. Solve for \( M \):

\(M = \frac{0.0821}{0.0821 \cdot 300}\)

\(M = \frac{0.0821}{24.63}\)

\(M \approx 0.00333\)

\(M = 0.33 \times 10^{-2}\)
Therefore, the concentration of the solution in moles per liter is approximately \( 0.33 \times 10^{-2}\) M.