NCERT Page No – 180
Q: A and B chambers, containing solutions are separated by a semi-permeable membrane.
(a) Solution of which chamber has a lower water potential?
Ans: B- chamber.
Reason: B-chamber contains more solute than that of A-chamber, therefore, it contains less free water molecule than that of the adjacent chamber. Thus, it has lower water potential than chamber A.
(b) Solution of which chamber has a lower solute potential?
Ans: B- chamber.
Reason: Refer NCERT page no 179, “the more the solute molecules, the lower is the solute potential“. Therefore, B-chamber contains more solute molecules, hence, it has lower solute potential than chamber A.
(c) In which direction will osmosis occur?
Ans: From A to B- chamber.
Reason: Water potential means, “tendency of water to move from higher solvent concentration than that of lower solvent concentration”. Chamber A contains less solute than that of B-chamber, therefore, A contains more free water (solvent) molecule than that of the B- chamber.
(d) Which solution has a higher solute potential?
Ans: A- chamber solution.
Reason: Refer NCERT page no 179, “the more the solute molecules, the lower is the solute potential“. It means, if, the number of solute molecule is less than that solution have more solute potential. Therefore, A-chamber contains less solute molecules, hence, it has more solute potential than chamber B.
(e) At equilibrium which chamber will have a lower solute potential?
Ans: The two chambers will have nearly the same water potential.
Reason: Refer NCERT page no 180, “at equilibrium the two chambers should have nearly the same water potential”.
(f) If one chamber has a water potential of -2000 kPa, and the other -1000 kPa, which is the chamber that has the higher water potential?
Ans: -1000 kPa
Reason: Refer NCERT page no 179, “the water potential of pure water at standard temperatures, which is not under any pressure, is taken to be zero.” Hence, more negative value means less water potential.
(g) What will be the direction of the movement of water when two solutions with water potential 0.2 MPa and water potential 0.1 MPa are separated by a selectively permeable membrane?
Ans: From water potential 0.2MPa to 0.1 MPa
Reason: 0.2 > 0.1. Movement of water takes place from higher water potential to lower water potential.