6. ⇒ (MHT CET 2023 9th May Evening Shift )

A solution of $8 g$ of certain organic compound in $2 {dm}^{3}$ water develops osmotic pressure $0.6 atm$ at $300 K$ . Calculate the molar mass of compound. [R = 0.082 atm dm $^{3}$ K $^{- 1}$ mol $^{- 1}$ ]

A. $148 g {mol}^{- 1}$

B. $164 g {mol}^{- 1}$

C. $172 g {mol}^{- 1}$

D. $180 g {mol}^{- 1}$

Correct Option is (B)

$\begin{aligned} π & = \frac{W_{2} RT}{M_{2} V} \\ ∴ M_{2} & = \frac{W_{2} RT}{π V} \\ ∴ M_{2} & = \frac{8 g \times 0.082 {dm}^{3} atm K^{- 1} {mol}^{- 1} \times 300 K}{0.6 atm \times 2 {dm}^{3}} \\ = 164 g {mol}^{- 1} \end{aligned}$

7. ⇒ (MHT CET 2023 9th May Morning Shift )

$0.2 M$ aqueous solution of glucose has osmotic pressure 4.9 atm at $300 K$ . What is the concentration of glucose if it has osmotic pressure $1.5 atm$ at same temperature?

A. $0.03 M$

B. $0.04 M$

C. $0.05 M$

D. $0.06 M$

Correct Option is (D)

$π = M \times R \times T$

$∴ M = \frac{π}{RT} = \frac{1.5}{0.082 \times 300} = 0.06 M$

8. ⇒ (MHT CET 2021 20th September Morning Shift )

Which of the following solutions does not flow in either direction, when separated by semipermeable membrane? (Molar mass : glucose = 180, urea = 60)

A. 18 g urea dm $^{- 3}$ and 18 g glucose dm $^{- 3}$

B. 6 g urea dm $^{- 3}$ and 36 g glucose dm $^{- 3}$

C. 6 g urea dm $^{- 3}$ and 24 g glucose dm $^{- 3}$

D. 12 g urea dm $^{- 3}$ and 36 g glucose dm $^{- 3}$

Correct Option is (D)

$n_{urea} = \frac{12}{60} = 0.2 and n_{glucose} = \frac{36}{180} = 0.2$

Now, $n_{urea} = n_{glucose}$

$∴ π_{urea} = π_{glucose}$

Hence, if these solutions are separated by a semipermeable membrane, there is no flow of solvent in either direction.

⇒Solution