The Effect of Water Velocity on Osmosis Karen Ni, Mara Tynan, and Joyce Yan
Dec 19, 2014
The Effect of Water Velocity on
OsmosisKaren Ni, Mara Tynan, and Joyce Yan
Hypothesis
• To understand how water velocity affects the rate of osmosis.
• As the velocity of the water increases, the rate of osmosis will increase.
• 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
Introduction
Materialso Three eggso 5% vinegar solutiono Beakers:
o 2-100mL o 1-500mLo 4-250mL
o 100mL graduated cylinder
o tap watero thermometero 2 funnelso cheesecloth
o tapeo 2 meter stickso rubber tubingo scissorso timero electronic mass
scaleo paper towels
Methodo Eggs deshelledo 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)
pictures of method
Results: 1.5 m
Trial: Initial Mass (grams)
Final Mass (grams)
Difference in 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
Results: 1 mTrial: Initial Mass
(grams)Final Mass (grams)
Difference in 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
Results: .5 m
Trial: Initial Mass (grams)
Final Mass (grams)
Difference in 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
Results: O m (Constant)Trial: Initial Mass
(grams)Final Mass (grams)
Difference in 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
Graph (With Control considered)
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.60
0.05
0.1
0.15
0.2
0.25
0.3
0.35
Average Difference of Mass in Different Heights of Water
Height Water was Dropped
Ave
rag
e D
iffe
ren
ce i
n M
ass
(gra
ms)
Graph (Without Control considered)
0.4 0.6 0.8 1 1.2 1.4 1.60
0.05
0.1
0.15
0.2
0.25
0.3
Average Difference in Mass in Different Heights of Water
Height Water was dropped (meters)
Ave
rag
e M
ass
Dif
fere
nce
(g
)
Full Scatter Plot (with trendline)
0.4 0.6 0.8 1 1.2 1.4 1.60
0.1
0.2
0.3
0.4
0.5
0.6
f(x) = 0.0666666666666667 x + 0.128888888888889R² = 0.0397719740156436
Difference in Mass over Different Heights
Height Water was dropped (meters)
Dif
fere
nce
in
Mas
s (g
ram
s)
• Averages of difference in mass seemed to increase slightly as height increasedo 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
oOne high outlier (0.55 g) skewed average
• Control group exhibited a greater average difference in mass than that of all heights.
Analysis
• Data does not support hypothesiso 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.
Conclusion
• Concentration of water in eggs
• Rubber tubing• Consistency of
pouring water
Errors
• More trials (10 if possible for each height)
• Greater range of tested heights (maybe 0.5- 5 m if possible)
Improvements