1. The Effect of Water
Velocity on Osmosis
Karen Ni, Mara Tynan, and Joyce Yan
2. Hypothesis
• To understand how water velocity
affects the rate of osmosis.
• As the velocity of the water increases,
the rate of osmosis will increase.
3. Introduction
• osmosis- movement of water across a
selectively permeable membrane from an
hypotonic to hypertonic environment
• velocity- speed with direction
• acceleration- Δvelocity
• increased height=faster final velocity
• faster velocity=water molecules pass
through membrane and enter cell faster
• Δd=.5at2+Vit
4. Materials o tape
o 2 meter sticks
o Three eggs
o rubber tubing
o 5% vinegar solution
o Beakers: o scissors
o 2-100mL o timer
o 1-500mL o electronic mass scale
o 4-250mL o paper towels
o 100mL graduated
cylinder
o tap water
o thermometer
o 2 funnels
o cheesecloth
5. Method
o Eggs deshelled
o For all trials
mass taken before and after
volume of remaining water measured
21oC water
60s
o Control
each egg placed in 250mL for 60s
o Experimental
Egg placed on the funnel with the cheesecloth
stretch over it.
Water poured down the tube at different
lengths (therefore speeds and velocities)
7. Results: 1.5 m
Trial: Initial Mass Final Mass Difference in
(grams) (grams) Mass (grams)
1 89.7 90.25 0.55
2 82.85 82.9 0.05
3 81.66 81.78 0.12
Average Difference in Mass: 0.24 grams
8. Results: 1 m
Trial: Initial Mass Final Mass Difference in
(grams) (grams) Mass (grams)
1 90.37 90.6 0.23
2 82.93 83.03 0.1
3 81.44 81.63 0.19
Average Difference in Mass: 0.17 grams
9. Results: .5 m
Trial: Initial Mass Final Mass Difference in
(grams) (grams) Mass (grams)
1 90.11 90.24 0.13
2 83.01 83.19 0.18
3 81.42 81.63 0.21
Average Difference in Mass: 0.17 grams
10. Results: O m (Constant)
Trial: Initial Mass Final Mass Difference in
(grams) (grams) Mass (grams)
1 83.65 84.08 0.43
2 82.47 82.75 0.28
3 80.93 81.17 0.24
Average Difference in Mass: 0.32 grams
11. Graph (With Control considered)
Average Difference of Mass in Different Heights of Water
0.35
0.3
Average Difference in Mass (grams)
0.25
0.2
0.15
0.1
0.05
0
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6
Height Water was Dropped
12. Graph (Without Control
considered)
Average Difference in Mass in Different Heights of Water
0.3
0.25
Average Mass Difference (g)
0.2
0.15
0.1
0.05
0
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6
Height Water was dropped (meters)
13. Full Scatter Plot (with trendline)
Difference in Mass over Different Heights
0.6
0.5
Difference in Mass (grams)
0.4
y = 0.066x + 0.128
0.3 R² = 0.039
0.2
0.1
0
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6
Height Water was dropped (meters)
14. Analysis
• Averages of difference in mass seemed to
increase slightly as height increased
o Individual trials showed that for the highest
height tested (1.5m) two of the trials in fact
displayed a lower difference than the
averages of all three heights
o One high outlier (0.55 g) skewed average
• Control group exhibited a greater average
difference in mass than that of all
heights.
15. Conclusion
• Data does not support hypothesis
o Lin-reg T test comes up with a p value of
0.332
Above the significance level- not sufficient
evidence to show that there was a positive
association between water velocity and rate of
osmosis.
