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प्रश्न
Answer the following.
Explain reverse osmosis.
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उत्तर
i. If a pressure larger than the osmotic pressure is applied to the solution side, then pure solvent from the solution passes into pure solvent side through the semipermeable membrane. This phenomenon is called reverse osmosis.
ii. For example, consider fresh water salt water separated by a semipermeable membrane. When the pressure larger than the osmotic pressure of a solution is applied to solution, pure water from salty water passes into fresh pure water through the membrane. Thus, the direction of osmosis can be reversed by applying a pressure larger than the osmotic pressure.
iii. The schematic set up for reverse osmosis is as follows:

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संबंधित प्रश्न
Determine the osmotic pressure of a solution prepared by dissolving 2.5 × 10−2 g of K2SO4 in 2L of water at 25°C, assuming that it is completely dissociated.
(R = 0.0821 L atm K−1 mol−1, Molar mass of K2SO4 = 174 g mol−1)
What happens when the external pressure applied becomes more than the osmotic pressure of solution?
Blood cells are isotonic with 0.9% sodium chloride solution. What happens if we place blood cells in a solution containing
(i) 1.2% sodium chloride solution?
(ii) 0.4% sodium chloride solution?
Determine the osmotic pressure of a solution prepared by dissolving 25 mg of K2SO4 in 2 liter of water at 25°C, assuming that it is completely dissociated.
Which of the following 0.1 M aqueous solutions will exert the highest osmotic pressure?
Calculate the mass of NaCl (molar mass = 58.5 g mol−1) to be dissolved in 37.2 g of water to lower the freezing point by 2°C, assuming that NaCl undergoes complete dissociation. (Kf for water = 1.86 K kg mol−1)
Calculate the mass of a compound (molar mass = 256 g mol−1) to be dissolved in 75 g of benzene to lower its freezing point by 0.48 K (Kf = 5.12 K kg mol−1).
Define the following term:
isotonic solution
Define the following term:
Hypotonic solution
Choose the most correct option.
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Choose the most correct option.
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Answer the following in one or two sentences.
What is osmotic pressure?
Answer the following in one or two sentences.
A solution concentration is expressed in molarity and not in molality while considering osmotic pressure. Why?
Answer the following.
What are isotonic and hypertonic solutions?
Answer the following.
The osmotic pressure of CaCl2 and urea solutions of the same concentration at the same temperature are respectively 0.605 atm and 0.245 atm, calculate van’t Hoff factor for CaCl2.
Answer the following.
How molar mass of a solute is determined by osmotic pressure measurement?
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Osmotic pressure of a solution is 0.0821 atm at a temperature of 300 K. The concentration in moles/litre will be:
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(iv) Solute is always same solvent may be different.
Give an example of a material used for making semipermeable membrane for carrying out reverse osmosis.
Discuss biological and industrial importance of osmosis.
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Derive an expression to calculate molar mass of non-volatile solute by osmotic pressure measurement.
Assertion (A) : Osmotic pressure is a colligative property.
Reason (R) : Osmotic pressure is proportional to the molality.
Determine the osmotic pressure of a solution prepared by dissolving 2.32 × 10−2 g of K2SO4 in 2L of solution at 25°C assuming that K2SO4 is completely dissociated.
(R = 0.082 L atm K−1 mol, Molar mass K2SO4 = 174 g mol−1)
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Define reverse osmosis.
Name the four colligative properties that are oftently used for determination of molecular mass.
How will you determine molar mass of solute from osmotic pressure?
Write the condition of reverse osmosis.
Calculate the osmotic pressure of 0.03 mole of non electrolyte solute dissolved in 0.1 dm3 of water at 300 K. [R = 0.082 dm3 atm mol-1 K-1]
The plot of osmotic pressure (π) vs concentration (mol L−1) for a solution gives a straight line with slope 25.73 L bar mol−1. The temperature at which the osmotic pressure measurement is done is ______.
(Use R = 0.083 L bar mol−1 K−1)
Calculate the osmotic pressure of 0.2 M aqueous solution of nonelectrolyte at 300 K.
[R = 0.082 atm dm3 mol−1K−1]
