When cells of the skeletal vacuole of a frog were placed in a series of $N a C l$ solutions of different concentration at $25^{\circ} C$ , it was observed microscopically that they remained unchanged in $0.7 % N a C l$ solution, shrank in more concentrated solutions, and swelled in more dilute solutions. Water freezes from the $0.7 %$ salt solution at $- {0.406}^{\circ} C$ . What is the osmotic pressure of the cell cytoplasm at $25^{\circ} C$ ? $K_{f} = 1.86 k g m o l^{- 1} K$ .

2.67 a t m

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5.34 a t m

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10.68 a t m

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12.87 a t m

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Solution

The correct option is B $5.34 a t m$
We know, $Δ T_{f} = i_{m} K_{f}$

Therefore, $i_{m} = \frac{0.406}{1.86} = 0.218$ mol/Kg

Osmotic pressure $= i_{c} R T = 0.218 \times 0.0821 \times 298 = 5.34$ atm

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The correct option is B 5.34atmWe know, ΔTf=imKf Therefore, im=0.4061.86=0.218 mol/KgOsmotic pressure =icRT=0.218×0.0821×298=5.34 atm

The correct option is B $5.34 a t m$
We know, $Δ T_{f} = i_{m} K_{f}$

Therefore, $i_{m} = \frac{0.406}{1.86} = 0.218$ mol/Kg

Osmotic pressure $= i_{c} R T = 0.218 \times 0.0821 \times 298 = 5.34$ atm