Question

Two arms of a U-tube are Separated by a semi permeable membrane. In the left arm is a sucrose solution with the solute potential of -0.5 MPa and the right arm is a difference sucrose solution with solute potential of -2.5 MPa.

(A) which arm of the tube has a higher concentration of sucrose?

(B) what is the molar contraction of sucrose on both sides of the membrane with temperature of 20 Celsius?

(C) in which direction does water movement occur?

(D) describe two ways water movements could be stopped?

Answer 1

A] The sucrose solution in the right arm of the U-tube has a higher concentration because the solute potential decreases as the concentration increases and the solution in the right arm has lower solute potential.   

C] Water moves through a semipermeable membrane by the process of osmosis. In this process, water molecoles move from where they are in higher concentration to where they are in less amount. In other words, water will move from a dilute solution to a concentrated solution through the semipermeable membrane till the concentration of both solutions attain equilibrium.

Hence, in the above set-up, water will move from the sucrose solution in the left arm of the U-tube to the solution in the right arm.

D] Two ways in which movement of water can be stopped are-- 1] by adding more sucrose to the solution in the left arm of the U-tube, till their concentration becomes same.

2] by increasing the pressure