at what height did the column of fluid in the tube stop rising?
Immediately mark the level of the solution in the glass tube by wrapping a second piece of wet string twice around the tube. Move the string to mark the starting level of the fluid in the glass tube. At 5 minute intervals, measure how far (in millimeters) the top of the column of solution in the tube has risen above the starting level. Record your observations in Table 1, then plot these results on Graph 1. 10. You will need to know: (a) When was the rate of rise the greatest? and (b) At what level (in mm) did the fluid in the tube stop rising (if it stopped)?
While monitoring the fluid level rising in the tube, begin Part II.
Table 1: Changes in internal pressure (height of fluid column)
Elapsed time (minutes)
Distance above mark (millimeters)
Change (# of mm) per 5 min. interval
0
5
10
15
20
25
30
35
40
45
49
From Graph 1, at what height did the column of fluid in the tube stop rising? _______mm This height can be used as a measure of the “osmotic pressure” inside our model cell in this particular “environment”.