2. LABORATORY CERTIFICATE
This is to certify that the project work
titled
Is a bonafide record done by: Sanjay PS
In partial fulfillment of the project in
Biology during the year 2015-2016
Mrs. Muthulakshmi (PGT Biology)
Signature
3. ACKNOWLEDGEMENT
First of all I convey my deep thanks to
Mrs.Muthulakshmi, Dept. of Biology
without whose guidance this project
would have become nothing. Last but not
the least I deeply acknowledge the help
given to me by my classmates whose
valuable tips and suggestions helped me
bring about such a project. I am deeply
indebted to them for also helping me
collect the relevant information from
many sources and also providing many
diagrams required to emphasise my
points.
5. Abstract
This science project was done to find out if
water will move through a semi permeable
membrane to a solution of higher
concentration. The science project experiment
was carried out using several eggs immersed in
distilled water and salt water.
6. Hypothesis
Water will pass through the shell of an egg, to
the side that has a solution of higher
concentration.
Scientific Terms
Osmosis, hypotonic, hypertonic, semi
permeable membrane, molecules
7. Background
Osmosis
Osmosis is the process by which water travels
through a semi permeable membrane from a
solution having a low concentration to a
solution having a higher concentration. The
solution with a low concentration is referred to
as a “hypotonic” solution, and the one with a
higher concentration is called “hypertonic”. The
purpose of this process is to equalize the
concentration of the solute on both sides of the
membrane.
8.
9.
10. The process of osmosis is very important for
living organisms. Cells use this process to pull
in and expel water from within the cell walls.
The walls of the cells act as the semi-permeable
membrane.
The membrane allows smaller molecules like
water to pass through but prevents larger
organic molecules from leaving the cell.
Plants use this process to absorb water from
the surrounding soil into their roots. Their roots
normally branch out in search of water and to
increase the surface area for absorbing water.
11. Materials
The materials required for this science project:
- 3 eggs
- 1200ml of distilled water
- 300gram of salt
- 1 measuring cylinder
- 3 beakers
- 1 weighing machine
- 1 spatula
- 3 piece of styrofoam cut to beaker size
- 1 black permanent marker pen
12. Procedure
1. For this science project, the independent
variable is the amount of salt in the water. The
dependent variable is the weight of the eggs
before and after being immersed in the
solution. This is determined by using a
weighing machine to check the weight of the
eggs. The constants (control variables) are the
amount of water used and the time during
which the eggs were immersed in the water.
2. The beakers are labeled A, B and C. 400ml
of water is filled into each of the beakers. In
the beaker labeled B, 100g of salt is poured in
13. and stirred using a spatula. Likewise, in
beaker C, 200g of salt is poured in and stirred
using the spatula.
3. The eggs are labeled A, B and C using the
marker pen. The weights of the eggs are
measured using the weighing machine and
recorded in the table given below.
4. Each of the eggs is then placed in beakers
labeled A, B and C. The cut styrofoam pieces
are placed inside the beakers to force the eggs
to remain fully immersed in the water. The
beakers and the eggs are put aside for 24
hours.
14. 5. After 24 hours, i the eggs are removed from
the beakers and wiped dry. Their weights are
checked again using the weighing machine. The
new weights are recorded in the table given
below.
6. The weight difference of the eggs before
they were immersed in the water and after 24
hours is calculated and recorded. The percent
of weight difference is then calculated as
follows:
% weight difference = (final egg weight – initial
egg weight) / initial egg weight x 100%
15. Observation
The results show that the weight of the egg
placed in distilled water has increased, while
the eggs placed in salt water had decreased in
weight.
Solution Initial
egg
weight
(g)
Final
egg
weight
(g)
Weight
difference
(g)
%
weight
change
Water 82.42 87.74 5.32 6.45%
Water &
100g salt
81.46 76.38 -5.08 -6.24%
Water &
200g salt
84.73 73.29 -11.44 -13.5%
16. The chart below represents the results of our
science project experiment.
17. Conclusion
Our hypothesis has been proven to be correct -
water will pass through the shell of an egg to
the side that has a solution of higher
concentration.
. In the case of the egg in beaker A, water from
outside the egg moved into the egg
increasing its weight. For the eggs in beakers B
and C, the water moved out of the
egg, diluting the salt water and reducing the
weight of the egg.
The osmosis and reverse osmosis process has
found its use in the water purification process.
18. Countries lacking in fresh water resources now
use this process for water recycling.
Also consider
The science project can be repeated by using
different soluble materials like sugar or syrup.
Repeat the science project experiment at
different temperatures to see if temperature
has any effect on the osmosis process.