Question

2 a student conducted an experiment with the setups shown in fig. 2.1. he measured the height of the liquid level in the capillary tube of each setup at different time intervals during the experiment.
capillary tube
liquid level at the start
10% sucrose
solution
visking tubing
distilled water
setup d
5% sucrose
solutions
setup e
fig. 2.1
the results of the experiment are shown in table 2.2.
table 2.2
time/min
height of liquid in the capillary tube / mm
setup d
setup e
0
0
0
20
140
40
40
150
50
60
150
50
(a) explain the change in the height of the liquid in the capillary tube of setup d during the first 20 minutes. 3
the vagont of the liquid in capillary tube increases to 140mm as time increase to 20minutes for setup d.

Explanation:

In setup D, the Visking tubing contains 10% sucrose solution, and the beaker has distilled water. The sucrose solution has a higher solute concentration (lower water potential) than distilled water. By osmosis, water moves from the beaker (higher water potential) into the Visking tubing (lower water potential). This influx of water increases the volume inside the tubing, causing the liquid level in the capillary tube to rise during the first 20 minutes.

Answer:

During the first 20 minutes in setup D, water moves into the Visking tubing (containing 10% sucrose solution) from the beaker (distilled water) by osmosis (as the sucrose solution has lower water potential than distilled water). This increases the volume in the tubing, raising the liquid level in the capillary tube.