OSMOSIS LABOr

Fresh Water vs. Sea Water

PROCEDURE

Write down Procedure (Notebook

pg. 32)

1.Make Table #1 (Notebook pg. 32)

2.Fill out table #1 with class

3.Make table #2 (Notebook pg. 33)

PROCEDURE

4. Make Hypothesis for each cup

(What will happen to the length of

the potato?)

5. Measure potato slices carefully (Put

in table #2)

6. Make sea water solutions (LABEL)

7. Drop potato slices into sea water

solutions and cover with plastic

wrap

PROCEDURE

MAKE SURE TO GET

THE CORRECT POTATO

INTO THE CORRECT

SOLUTION

FRESH WATER VS. SEA WATER

A shipwrecked

sailor is stranded

on a small desert

island with no

fresh water to

drink.

FRESH WATER VS. SEA WATER

She knows she could

last without food for up

to a month, but if she

didn’t have water to

drink she would be

dead within a week.

FRESH WATER VS. SEA WATER

Hoping to

postpone the

inevitable,

her thirst

drove her to

drink the

salty

seawater.

FRESH WATER VS. SEA WATER

She was dead in two days.

FRESH WATER VS. SEA WATER

Why do you think

drinking

seawater killed

the sailor faster

than not drinking

any water at all?

FRESH WATER VS. SEA WATER

Today we explore the cause of

the sailor’s death. We’ll

prepare solutions of salt

water to represent the sea,

and we’ll cut up slices of

potato to represent the sailor.

FRESH WATER VS. SEA WATER

Potatoes are made of cells, as is the

sailor!

OBJECTIVE

To determine the cause of the sailor’s death, we will

determine the effects of salt water on slices of

potato. Our assumption is that potato cells will

behave like the sailor’s cells in her body. We will

compare salt water to fresh water so we can see if

there is any effect caused by the salt in the water.

The fresh water acts as a control in this experiment.

TABLE 1

Percent Sea Water

Vol. of 100% Salt Water (ml)

Vol. of Fresh Water (ml) Total Vol. (ml)

 10% Sea Water 

     

 5% Sea Water 

     

 1% Sea Water 

     

 Fresh Water 

     

TABLE 1

Percent Sea Water

Vol. of 100% Salt Water (ml)

Vol. of Fresh Water (ml) Total Vol. (ml)

 10% Sea Water 

     100 ml

 5% Sea Water 

     100 ml

 1% Sea Water 

     100 ml

 Fresh Water 

     100 ml

TABLE 1

Percent Sea Water

Vol. of 100% Salt Water (ml)

Vol. of Fresh Water (ml) Total Vol. (ml)

 10% Sea Water 

    100 ml 

 5% Sea Water 

    100 ml 

 1% Sea Water 

     100 ml

 Fresh Water 

 0 ml    

100 ml

TABLE 1

Percent Sea Water

Vol. of 100% Salt Water (ml)

Vol. of Fresh Water (ml) Total Vol. (ml)

 10% Sea Water 

    100 ml 

 5% Sea Water 

    100 ml 

 1% Sea Water 

     100 ml

 Fresh Water 

 0 ml

 100 ml

 100 ml

TABLE 1

Percent Sea Water

Vol. of 100% Salt Water (ml)

Vol. of Fresh Water (ml) Total Vol. (ml)

 10% Sea Water 

 10 ml   100 ml 

 5% Sea Water 

     100 ml

 1% Sea Water 

     100 ml

 Fresh Water 

 0 ml

 100 ml

 100 ml

TABLE 1

Percent Sea Water

Vol. of 100% Salt Water (ml)

Vol. of Fresh Water (ml) Total Vol. (ml)

 10% Sea Water 

 10 ml

 90 ml 100 ml 

 5% Sea Water 

     100 ml

 1% Sea Water 

     100 ml

 Fresh Water 

 0 ml

 100 ml

 100 ml

TABLE 1

Percent Sea Water

Vol. of 100% Salt Water (ml)

Vol. of Fresh Water (ml) Total Vol. (ml)

 10% Sea Water 

 10 ml

 90 ml

 100 ml

 5% Sea Water 

 5 ml    

100 ml

 1% Sea Water 

     100 ml

 Fresh Water 

 0 ml

 100 ml

 100 ml

TABLE 1

Percent Sea Water

Vol. of 100% Salt Water (ml)

Vol. of Fresh Water (ml) Total Vol. (ml)

 10% Sea Water 

 10 ml

 90 ml

 100 ml

 5% Sea Water 

 5 ml

 95 ml

 100 ml

 1% Sea Water 

     100 ml

 Fresh Water 

 0 ml

 100 ml

 100 ml

TABLE 1

Percent Sea Water

Vol. of 100% Salt Water (ml)

Vol. of Fresh Water (ml) Total Vol. (ml)

 10% Sea Water 

 10 ml

 90 ml

 100 ml

 5% Sea Water 

 5 ml

 95 ml

 100 ml

 1% Sea Water 

 1 ml    

100 ml

 Fresh Water 

 0 ml

 100 ml

 100 ml

TABLE 1

Percent Sea Water

Vol. of 100% Salt Water (ml)

Vol. of Fresh Water (ml) Total Vol. (ml)

 10% Sea Water 

 10 ml

 90 ml

 100 ml

 5% Sea Water 

 5 ml

 95 ml

 100 ml

 1% Sea Water 

 1 ml

 99 ml

 100 ml

 Fresh Water 

 0 ml

 100 ml

 100 ml

TABLE 2Sample Initial

Length (Day 1)

Final Length (Day 2)

Change in

Length

  Tonicity  

        Hypo- Iso- Hyper-

10% Salt

cm.          

5% Salt cm.          

1% Salt cm.          

Fresh Water

 cm.

         

HYPOTHESIS

1. I think that the 10% salt water solution will cause the

potato slice to…

2. I think that the 5% salt water solution will cause the potato

slice to…

3. I think that the 1% salt water solution will cause the potato

slice to…

4. I think that the fresh water solution will cause the potato

slice to…

OSMOSIS LAB DAY 2

(Put this information on pg. 35 in your notebook)

1.Collect cups

2.Remove potato slices carefully

3.Measure slices accurately

4.Fill in Data Table #2

DATA TABLE 2

Sample

Initial Lengt

h (Day

1)

Final Lengt

h (Day

2)

Change in

Length

  Tonicity

 

        Hypo- Iso- Hyper-

10% Salt

cm.          

5% Salt

cm.          

1% Salt

cm.          

Fresh Water

 cm.

         

DATA TABLE 2

Sample

Initial Lengt

h (Day

1)

Final Lengt

h (Day

2)

Change in

Length

  Tonicity

 

        Hypo- Iso- Hyper-

10% Salt

4.2 cm.

         

5% Salt

cm.          

1% Salt

cm.          

Fresh Water

 cm.

         

DATA TABLE 2

Sample

Initial Lengt

h (Day

1)

Final Lengt

h (Day

2)

Change in

Length

  Tonicity

 

        Hypo- Iso- Hyper-

10% Salt

4.2 cm.

 3.9 cm.

       

5% Salt

cm.          

1% Salt

cm.          

Fresh Water

 cm.

         

DATA TABLE 2

Sample

Initial Lengt

h (Day

1)

Final Lengt

h (Day

2)

Change in

Length

  Tonicity

 

        Hypo- Iso- Hyper-

10% Salt

4.2 cm.

 3.9 cm

- .3 cm

     

5% Salt

cm.          

1% Salt

cm.          

Fresh Water

 cm.

         

DATA TABLE 2

Sample

Initial Lengt

h (Day

1)

Final Lengt

h (Day

2)

Change in

Length

  Tonicity

 

        Hypo- Iso- Hyper-

10% Salt

4.2 cm.

 3.9 cm

- .3 cm

     X

5% Salt

cm.          

1% Salt

cm.          

Fresh Water

 cm.

         

DATA TABLE 2

Sample

Initial Lengt

h (Day

1)

Final Lengt

h (Day

2)

Change in

Length

  Tonicity

 

        Hypo- Iso- Hyper-

10% Salt

4.2 cm.

 3.9 cm

- .3 cm

     X

5% Salt

3.8 cm.

         

1% Salt

cm.          

Fresh Water

 cm.

         

DATA TABLE 2

Sample

Initial Lengt

h (Day

1)

Final Lengt

h (Day

2)

Change in

Length

  Tonicity

 

        Hypo- Iso- Hyper-

10% Salt

4.2 cm.

 3.9 cm

- .3 cm

     X

5% Salt

3.8 cm.

 4.0 cm

       

1% Salt

cm.          

Fresh Water

 cm.

         

DATA TABLE 2

Sample

Initial Lengt

h (Day

1)

Final Lengt

h (Day

2)

Change in

Length

  Tonicity

 

        Hypo- Iso- Hyper-

10% Salt

4.2 cm.

 3.9 cm

- .3 cm

     X

5% Salt

3.8 cm.

 4.0 cm

 + .2 cm

     

1% Salt

cm.          

Fresh Water

 cm.

         

DATA TABLE 2

Sample

Initial Lengt

h (Day

1)

Final Lengt

h (Day

2)

Change in

Length

  Tonicity

 

        Hypo- Iso- Hyper-

10% Salt

4.2 cm.

 3.9 cm

- .3 cm

     X

5% Salt

3.8 cm.

 4.0 cm

 + .2 cm

 X    

1% Salt

cm.          

Fresh Water

 cm.

         

OSMOSIS LAB DAY 2

5. Throw potato slices and plastic wrap in

garbage

6. Dump out cups and stack on lab table

7. Answer questions on last page of lab handout

(notebook pg. 34)

8. Make Bar Graph of results from Data Table

#2 for Day 1 and Day 2 potato lengths – put

in notebook pg. 34 or 35

BAR GRAPH

10% Salt 5% Salt 1% Salt Fresh0

0.51

1.52

2.53

3.54

4.5 4.23.8 4 43.9 4 3.9 4

InitialFinal

FORMAL LAB REPORT

• Rough draft – Written in notebook

• Final draft – Written in the following format

FINAL DRAFT

PROBLEM:

1. The problem we are trying to solve is…

2. This problem is important because…

3. The information that is important to know before

we begin is…

4. The control in this experiment is…A. This is the control in the experiment

because…

FINAL DRAFT

PROBLEM:

5. My hypothesis was…A. I made the hypothesis that the 10% salt solution

water would cause the potato slice to…B. I made the hypothesis that the 5% salt solution

water would cause the potato slice to…C. I made the hypothesis that the 1% salt solution

water would cause the potato slice to…D. I made the hypothesis that the fresh water would

cause the potato slice to…

PROCEDURE

1. Materials List – List all materials used in the

experiment.

2.List in order how the experiment was performed.A. The first thing I had to do was ____________B. The next thing I had to do was ____________C. After that I ________________D. Finally I _______________

RESULTS

1.What quantitative and qualitative observations were

you able to make? (list)• Quantitative observations are number type

observations. • Qualitative observations are opinions or color

observations.

2. Data table (taken from your notebook)

3. Graph

OBSERVATIONS AND CONCLUSIONS

1. When the potato slices sat in the water overnight they

_______________A. I think the potato slices did this because ____________

2.Is diffusion, osmosis, or active transport responsible for the

changes in the slices?A. Define:

a. Diffusionb. Osmosisc. Active transport

OBSERVATIONS AND CONCLUSIONS

3. The ______ solution is isotonic to potato cells.A. I know that the solution _______ is isotonic to the potato cells because _____________

4.Define:A. HypertonicB. HypotonicC. Isotonic

OBSERVATIONS AND CONCLUSIONS

5. The sailor died more quickly drinking salt water than

not drinking any water at all because _______________.

6. I think the sailor died from ____________

7. My hypothesis was correct. OR My hypothesis was

not correct.A. My hypothesis was correct because __________. OR My hypothesis was not correct because ____________.