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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
Which of the following is not a colligative property?
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?
A solution containing 15 g urea (molar mass = 60 g mol–1) per litre of solution in water has the same osmotic pressure (isotonic) as a solution of glucose (molar mass = 180 g mol–1) in water. Calculate the mass of glucose present in one litre of its solution.
At 300 K, 36 g of glucose present in a litre of its solution has an osmotic pressure of 4.98 bar. If the osmotic pressure of the solution is 1.52 bars at the same temperature, what would be its concentration?
Determine the amount of CaCl2 (i = 2.47) dissolved in 2.5 litre of water such that its osmotic pressure is 0.75 atm at 27°C.
Define osmotic pressure.
Define Semipermeable membrane
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
Choose the most correct option.
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Answer the following.
What are isotonic and hypertonic solutions?
Answer the following.
A solvent and its solution containing a nonvolatile solute are separated by a semipermeable membrane. Does the flow of solvent occur in both directions? Comment giving a reason.
Answer the following.
How molar mass of a solute is determined by osmotic pressure measurement?
An aqueous solution of a certain organic compound has a density of 1.063 g mL-1 , osmotic pressure of 12.16 atm at 25 °C and a freezing point of 1.03 °C. What is the molar mass of the compound?
Which of the following statements is applicable for 0.1 M urea solution and 0.1 M sucrose solution?
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Explain the phenomenon of osmosis.
Which of the following is a colligative property?
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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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In isotonic solutions:
(i) Solute and solvent both are same.
(ii) Osmotic pressure is same.
(iii) Solute and solvent may or may not be same.
(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.
Match the items given in Column I and Column II.
| Column I | Column II |
| (i) Saturated solution | (a) Solution having same osmotic pressure at a given temperature as that of given solution. |
| (ii) Binary solution | (b) A solution whose osmotic pressure is less than that of another. |
| (iii) Isotonic solution | (c) Solution with two components. |
| (iv) Hypotonic solution | (d) A solution which contains maximum amount of solute that can be dissolved in a given amount of solvent at a given temperature. |
| (v) Solid solution | (e) A solution whose osmotic pressure is more than that of another. |
| (vi) Hypertonic solution | (f) A solution in solid phase. |
Discuss biological and industrial importance of osmosis.
How can you remove the hard calcium carbonate layer of the egg without damaging its semiprermiable membrane? Can this egg be inserted into a bottle with a narrow neck without distorting its shape? Explain the process involved.
Which of the following colligative property can provide molar mass of proteins (or polymers or colloids) with greatest precision?
Isotonic solutions have same
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Assertion (A) : Osmotic pressure is a colligative property.
Reason (R) : Osmotic pressure is proportional to the molality.
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How will you determine molar mass of solute from osmotic pressure?
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(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]
