Osmosis and osmotic pressure — practice questions

Question 1 · difficulty L2 · understanding

The osmotic pressure of a living cell is 12 atm at 300 K. The strength of sodium chloride solution that is isotonic with the living cell at this temperature is ________ g L -1 . (Nearest integer) Given : R = 0.08 L atm K -1 mol -1 Assume complete dissociation of NaCl (Given: Molar mass of Na and Cl are 23 and 35.5 g mol -1 respectively.)

Question 2 · difficulty L2 · understanding

An artificial cell is made by encapsulating $$0.2 \mathrm{~M}$$ glucose solution within a semipermeable membrane. The osmotic pressure developed when the artificial cell is placed within a $$0.05 \mathrm{~M}$$ solution of $$\mathrm{NaCl}$$ at $$300 \mathrm{~K}$$ is ________ $$\times 10^{-1}$$ bar. (nearest integer). [Given : $$\mathrm{R}=0.083 \mathrm{~L} \mathrm{~bar} \mathrm{~mol}^{-1} \mathrm{~K}^{-1}$$ ] Assume complete dissociation of $$\mathrm{NaCl}$$

Question 3 · difficulty L2 · understanding

The osmotic pressure of a dilute solution is $$7 \times 10^5 \mathrm{~Pa}$$ at $$273 \mathrm{~K}$$. Osmotic pressure of the same solution at $$283 \mathrm{~K}$$ is _________ $$\times 10^4 \mathrm{Nm}^{-2}$$.

Question 4 · difficulty L2 · understanding

An aqueous solution of volume $$300 \mathrm{~cm}^{3}$$ contains $$0.63 \mathrm{~g}$$ of protein. The osmotic pressure of the solution at $$300 \mathrm{~K}$$ is 1.29 mbar. The molar mass of the protein is ___________ $$\mathrm{g} ~\mathrm{mol}^{-1}$$ Given : R = 0.083 L bar K$$^{-1}$$ mol$$^{-1}$$

Question 5 · difficulty L2 · understanding

At $$27^{\circ} \mathrm{C}$$, a solution containing $$2.5 \mathrm{~g}$$ of solute in $$250.0 \mathrm{~mL}$$ of solution exerts an osmotic pressure of $$400 \mathrm{~Pa}$$. The molar mass of the solute is ___________ $$\mathrm{g} \mathrm{~mol}^{-1}$$ (Nearest integer) (Given : $$\mathrm{R}=0.083 \mathrm{~L} \mathrm{~bar} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}$$)

Question 6 · difficulty L2 · understanding

The osmotic pressure of blood is 7.47 bar at 300 K. To inject glucose to a patient intravenously, it has to be isotonic with blood. The concentration of glucose solution in gL $$-$$1 is _____________. (Molar mass of glucose = 180 g mol $$-$$1 , R = 0.083 L bar K $$-$$1 mol $$-$$1 ) (Nearest integer)

Question 7 · difficulty L2 · understanding

1.46 g of a biopolymer dissolved in a 100 mL water at 300 K exerted an osmotic pressure of 2.42 $$\times$$ 10 $$-$$3 bar. The molar mass of the biopolymer is _____________ $$\times$$ 10 4 g mol $$-$$1 . (Round off to the Nearest Integer) [Use : R = 0.083 L bar mol $$-$$1 K $$-$$1 ]

Question 8 · difficulty L2 · understanding

Solution A is prepared by dissolving 1 g of a protein (molar mass = 50,000 g mol -1 ) in 0.5 L of water at 300 K. Its osmotic pressure is $x$ bar. Solution B is made by dissolving 2 g of the same protein in 1 L of water at 300 K. Osmotic pressure of solution B is $y$ bar. Entire solution of A is mixed with entire solution of B at the same temperature. The osmotic pressure of resultant solution is $z$ bar. $x$, $y$ and $z$ respectively are: (R = 0.083 L bar mol -1 K -1 )

• A. $9.96 \times 10^{-4};\;9.96 \times 10^{-4};\;9.96 \times 10^{-4}$
• B. $9.96 \times 10^{-4};\;9.96 \times 10^{-4};\;19.92 \times 10^{-4}$
• C. $4.98 \times 10^{-4};\;4.98 \times 10^{-4};\;9.96 \times 10^{-4}$
• D. $4.98 \times 10^{-4};\;4.98 \times 10^{-4};\;4.98 \times 10^{-4}$

Question 9 · difficulty L2 · understanding

A solution is prepared by dissolving 0.3 g of a non-volatile non-electrolyte solute 'A' of molar mass $60 \mathrm{~g} \mathrm{~mol}^{-1}$ and 0.9 g of a non-volatile non-electrolyte solute ' B ' of molar mass $180 \mathrm{~g} \mathrm{~mol}^{-1}$ in $100 \mathrm{~mL} \mathrm{H}_2 \mathrm{O}$ at $27^{\circ} \mathrm{C}$. Osmotic pressure of the solution will be [Given: $\mathrm{R}=0.082 \mathrm{~L} \mathrm{~atm} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}$ ]

• A. 2.46 atm
• B. 0.82 atm
• C. 1.47 atm
• D. 1.23 atm

Question 10 · difficulty L3 · understanding

20 g hemoglobin in a 1 L aqueous solution $(\mathrm{A})$ at 300 K is separated from pure water by semi permeable membrane. At equilibrium the height of solution in a tube dipped in a solution (A) is found to be 80.0 mm higher than the tube dipped in water. The molar mass of hemoglobin is $\_\_\_\_$ $\mathrm{kg} \mathrm{mol}^{-1}$. (Nearest integer) (Given : $\mathrm{g}=10 \mathrm{~m} \mathrm{~s}^{-2}, \mathrm{R}=8.3 \mathrm{kPa} \mathrm{dm} \mathrm{K}^{-1} \mathrm{~mol}^{-1}$, density of solution $=1000 \mathrm{~kg} \mathrm{~m}^{-3}$ )