Post on 19-Dec-2014
description
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
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 0.2 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 = 0.0397719740156436f(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