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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)
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?
Calculate the osmotic pressure in pascals exerted by a solution prepared by dissolving 1.0 g of polymer of molar mass 185,000 in 450 mL of water at 37°C.
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.
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)
Define the following term:
isotonic solution
Choose the most correct option.
In calculating osmotic pressure the concentration of solute is expressed in _______.
Answer the following in one or two sentences.
What is osmotic pressure?
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.
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?
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?
Explain the osmotic pressure of a solution with the help of a thistle tube.
Explain the phenomenon of osmosis.
Define Osmosis.
Two solutions have different osmotic pressures. The solution of higher osmotic pressure is called ____________.
At constant temperature the osmotic pressure of a solution is ____________.
20 g of a substance were dissolved in 500 mL of water and the osmotic pressure of the solution was found to be 600 mm of mercury at 15°C. The molecular weight of the substance is ______.
The temperature at which 10% aqueous solution of (W/V) of glucose will show the osmotic pressure of 16.4 atoms is: (R = 0.082 L atom K−1 mol−1)
Which of the following statements is false?
Isotonic solutions must have the same:
(i) solute
(ii) density
(iii) elevation in boiling point
(iv) depression in freezing point
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.
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.
Osmotic pressure of a solution increases if
Which of the following colligative property can provide molar mass of proteins (or polymers or colloids) with greatest precision?
Isotonic solutions have same
In Isotonic solution
The vapour pressure of water is 12.3 k pa at 300 k. Calculated the vapour pressure of molal solution in it.
Osmotic pressure of a solution containing 2 g dissolved protein per 300 cm3 of solution is 20 mm of Hg at 27°C. The molecular mass of protein is ______.
The following solutions were prepared by dissolving 10 g of glucose (C6H12O6) in 250 ml of water (P1), 10 g of urea (CH4N2O) in 250 ml of water (P2) and 10 g of sucrose (C12H22O11) in 250 ml of water (P3). The right option for the decreasing order of osmotic pressure of these solutions is
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)
A solution containing 10 g glucose has osmotic pressure 3.84 atm. If 10 g more glucose is added to the same solution, what will be its osmotic pressure? (Temperature remains constant)
Prove that: M2 = `(W_2RT)/(πV)`.
Arrange the following solutions in the order of increasing osmotic pressure (π) assuming complete ionization.
- 0.5M Li2 SO4
- 0.5M KCl
- 0.5M Al2 (SO4)3
- 0.1 M BaCl2
Define reverse osmosis.
Name the four colligative properties that are oftently used for determination of molecular mass.
Write the condition of reverse osmosis.
The 'X' g nonvolatile solute having molar mass 196 g mol-1 is dissolved in 3 dm³ water. Calculate the value of 'X' if resulting solution has osmotic pressure 0.8 atm at 300 К.
(R = 0.0821dm³ atm K-1 mol-1)
Calculate the osmotic pressure of 0.2 M aqueous solution of nonelectrolyte at 300 K.
[R = 0.082 atm dm3 mol−1K−1]
