Advertisements
Advertisements
प्रश्न
Explain the osmotic pressure of a solution with the help of a thistle tube.
Advertisements
उत्तर
- Osmosis can be demonstrated with the following experimental set up in which a semipermeable membrane is firmly fastened across the mouth of thistle tube. The solution of interest is placed inside an inverted thistle tube. This part of the tube and the membrane are then immersed in a container of pure water.

Osmosis and osmotic pressure - As a result of osmosis, some of the solvent passes through the membrane into the solution. It causes the liquid level in the tube to rise. The liquid column in the tube creates hydrostatic pressure that pushes the solvent back through the membrane into the container. The column of liquid in the tube continues to rise and eventually stops rising. At this stage hydrostatic pressure developed is sufficient to force solvent molecules back through the membrane into the container at the same rate they enter the solution.
- Thus, an equilibrium is established where rates of forward and reverse passages are equal. The height of liquid column in the tube remains constant. This implies that the hydrostatic pressure has stopped osmosis.
- The hydrostatic pressure that stops osmosis is an osmotic pressure (π) of the solution. The hydrostatic pressure is equal to hρg, where, h is the height of the liquid column in the tube, ρ is density of solution and g is acceleration due to gravity.
APPEARS IN
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)
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.
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.
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.
Which of the following 0.1 M aqueous solutions will exert the highest osmotic pressure?
Define the following term:
isotonic solution
Define the following term:
Hypotonic solution
Choose the most correct option.
A living cell contains a solution which is isotonic with 0.3 M sugar solution. What osmotic pressure develops when the cell is placed in 0.1 M KCl solution at body temperature?
Choose the most correct option.
The osmotic pressure of blood is 7.65 atm at 310 K. An aqueous solution of glucose isotonic with blood has the percentage (by volume)________.
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.
What are hypertonic solutions?
Explain the phenomenon of osmosis.
Define Osmosis.
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 average osmotic pressure of human blood is 7.8 bar at 37°C. What is the concentration of an aqueous NaCl solution that could be used in the blood stream?
A solution containing 10 g per dm3 of urea (molar mass 60 g mol−1) is isotonic with 5% solution of non-volatile solute, MB of solute 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?
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. |
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
Blood cells retain their normal shape in solution which are
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
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)
Isotonic solutions are the solutions having the same ______.
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)
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
How will you determine molar mass of solute from osmotic pressure?
Write the condition of reverse osmosis.
