Osmosis Lab By: Andy Guidas, Christina Szabados, Sam Bonelli

Osmosis Lab
By: Andy Guidas,
Christina Szabados, Sam
Bonelli
Question
 Do
different types of solute
affect osmosis in potatoes?
Hypothesis and Purpose
Hypothesis: If we test the rate of osmosis
in solutions of glucose, sodium chloride,
distilled water and sucrose, then the
potato in the sodium chloride solution
will loose water, while the other potatoes
will gain water.
 The purpose of our experiment was to
determine how types of solvent can
affect osmosis.

Controls and Variables
Controls:
 Potato size
 Concentration of solution
 Time allowed for osmosis
 Temperature
Variables:
 Type of solvent
1.
2.
3.
4.
5.
Procedure
Prepare solutes by dissolving 5g of solute into
50mL of water. Then stir to dissolve, and add
water to the mixture up to 100mL.
Use the 5mm diameter specimen extractor to
make 4 potato cylinders.
Use a scale to weigh each cylinder. Record this
under Initial Mass in your data table.
Add one potato cylinder to each cup of solute.
Let sit for 30 minutes. After the time has
elapsed, dry off the potato cylinders and record
their Final Weight in your data table.
Collected Data:
Solute (5%)
Initial
Weight
Final
Weight
% Change
Glucose
4.6g
4.6g
0%
Sucrose
Sodium
Chloride
4.0g
4.1g
2.44%
3.0g
2.7g
-11.10%
Distilled H2O
4.3g
4.7g
4.25%
Pictorials
Conclusions

The purpose of this lab was to determine if the
solvent affects the rate of osmosis. From our
data we found that the potato in the sodium
chloride solution had 11.10% less mass after
30 minutes. While in the water and sucrose
the mass of the potato was greater (2.44%
and 4.25%)than before.
What We Learned





This data shows that there was more salt in the 5% sodium
chloride solution than in the potato because water went out of
the potato.
There was an equal amount of glucose in the glucose
solution and potato because there was no change in mass.
There was more sucrose in the potato than in the sucrose
solution because water went into the potato.
There was a greater amount of particles in the potato that in
the water because water went into the potato.
This shows that our hypothesis was for the most part correct,
except that the nothing happened to the solution of glucose.
Further Conclusions

Our data shows that in sodium chloride the
water went from the hypertonic solution to
the hypotonic potato. While in the sucrose
and water the water went from the hypotonic
solution to the hypertonic potato.
Experimental Errors


It was difficult to get the potatoes to be the
same size, this could have affected our
results because this change in size affects
surface area, which could affect the rate of
osmosis.
If we did not dry off the potatoes enough this
could cause the potato to be a great mass than
it actually was.
Things to Change


I think it would be beneficial if we had a
better way to make the potatoes the same size,
like also measuring their length.
It might also be interesting to try other types
of solution to see how the results differ or to
try mixing different types of solutions to see
if this had an affect.
Bibliography
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http://nutritionresearchcenter.org/healthnew
s/wp-content/uploads/2008/02/cs_mph.jpg
http://easycoffee.com.au/images/T/WhiteSu
gar500g.jpg
http://www.biochem.arizona.edu/classes/bioc
462/462bh2008/462bhonorsprojects/462bh
onors2007/gsantarelli/glucose.gif
http://www.tulpehockenwater.com/images/pr
oducts/gallon_big.jpg