diffusion egg presentation

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