Essay Color Key

Free Essays
Unrated Essays
Better Essays
Stronger Essays
Powerful Essays
Term Papers
Research Papers




Osmosis in Carrots

Rate This Paper:

Length: 2244 words (6.4 double-spaced pages)
Rating: Red (FREE)      
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Osmosis in Carrots

Background

Osmosis is the diffusion of water from a dilute solution to a more
concentrated solution through a partially permeable membrane, which
allows the pass of water molecules but not solute molecules.

[IMAGE][IMAGE][IMAGE][IMAGE][IMAGE][IMAGE][IMAGE][IMAGE]If a cell is
placed in a less concentrated solution water enters because the less
concentrated solution will have a high concentration of water than the
inside of the cell. Once the cell takes in maximum water the cell
becomes turgid.

If the cell was to be placed in a high concentrated solution, water
would leave the cell because the cell would contain a low concentrated
solution. So in the low concentrated solution there will be a high
concentration of water and in the high concentrated solution there
will be a low concentration of water. So what is happening is water is
moving from a high concentration, i.e. a dilute solution to a more
concentrated solution.

Preliminary Work on Osmosis

I am going to test carrots in a small osmosis experiment to see how
the experiment works with carrots and salt solution and water.

Variables

1) Temperature - Keep the same

2) Number of days left soaking - Keep the same

3) Size of beaker - Keep the same

4) Size of carrots - Keep the same

5) Concentration of salt solution - Change

Apparatus

Top Pan Balance - to weight carrots

Measuring Cylinders - to measure solution and distilled water

Dropper Pipettes - to ensure accurate measuring of solutions

Distilled Water - to test how osmosis works in carrots

1M Salt Solution - to test how osmosis works in carrots

Carrots Disks - to weigh carrot mass in

Beakers - to soak carrots in

Goggles - to protect eyes

Diagram

Method

Using a measuring cylinder and dropper pipette I accurately measured
50cm³ of distilled water and 1M solution of sodium chloride then
separately poured them into two separate beakers. The beakers were of
the same size. I also got two pieces of carrots which were
approximately the same size. Then I weighed and recorded the mass of
each piece of carrot separately using a disc and top pan balance.
Following that using the carrot disc I took the carrots to the beakers
and dropped them in at the same time, one in each. I left the beakers
in the same place to ensure the temperature stays the same in both
beakers. After a day of soaking I took the carrots out and dabbed them
with a paper towel so the external water or solution is taken of. Then
I reweighed the mass of the carrots and recorded it on a table.

Results Table

Conclusion

In this preliminary experiment I learned that osmosis does take place
in carrots using sodium chloride (NaCl) and distilled water (pure
H²O). The carrot in the distilled water gained mass. As I have used
the results of several groups I can see the carrot in the distilled
water always gained mass, which meant water was entering the carrot
leaving the carrot cells turgid. This took place because the distilled
water was a 100% concentration of water, where as in the carrot the
cells had a dilute solution with a less concentration of water. So the
law of osmosis took place, the water moved from a high concentration
to a low concentration.

The carrot in my NaCl solution loss mass and so did the rest of the
group's carrots in the NaCl solution, loss mass. The reason for this
was the 1M NaCl was a more concentrated solution than the carrot so
water left the cells in the carrot leaving the cells plasmolysed.

As osmosis takes place in carrots I have decided to conduct my main
experiment using carrots. The range of solution I am going to use is
from 0-2M of NaCl. I will keep errors minimized in measurement of mass
by instead of repeating every individual carrot in the specific
solutions; I will use four carrots instead. Also this will benefit me
because of the lack of equipment and time I have.

Main Experiment

Aim

To find out the effect of 0-2M NaCl solution has on osmosis in
carrots.

Variables

1) Temperature - Keep the same

2) Number of days left soaking - Keep the same

3) Size of beaker - Keep the same

4) Size of carrots - Keep the same

5) Surface area - Kept the same

6) Concentration of salt solution - Change

Predictions

My predictions are the carrots in the solutions lower than 1M solution
will have a mass increase and carrots in solutions of 1M or above will
have a mass decrease. I also predict that osmosis will take place in
all the carrots, which ever of the solutions placed in. I have based
my predictions on my preliminary work, the more concentrated the salt
solution, the net movement of water will be out of the cell and so
carrot discs will show more decrease in mass the stronger the salt
solution.

In water, the net movement of water by osmosis will be into the cell
so the carrots will show an increase in mass. When the salt
concentration inside the carrot equals that of the salt solution
outside in the beaker, then no change in mass will be observed.

Fair Testing

To ensure my experiment is fair I must carry out several procedures.
Many of these procedures will involve my variables. The temperature
will have to be kept the same to do this I will have to place all
beakers at the same place. The size of beaker, surface area, size of
carrots will also have to stay the same to make sure any of the
carrots are not getting a advantage or disadvantage allowing osmosis
to take place efficiently or inefficiently. All the carrots will also
have to be dropped in the solutions and taken out the same time so the
carrots have the same amount of soaking time. The only variable that
will have to change is the concentration of the NaCl solution, which I
intend to produce my self by accurately measuring so my results are
guaranteed to be as accurate as possible.

Safety

Gaining experience in the trial run I have learned there are not many
safety hazards in this experiment that we should fear from. I have
only picked up that goggles is necessary, in case u were to spill the
NaCl all over your face while reading how much you have poured into
the measuring cylinder. Also it would be wise to keep the beakers in
the centre of the work surface, which will help to avoid knocking the
beakers over and shattering them as they are made out of glass. If
this was to happen I would inform the teacher who will clear it up.

Apparatus

Top Pan Balance - to weight carrots

Measuring Cylinders - to measure solution and distilled water

Dropper Pipettes - to ensure accurate measuring of solutions

0-2M NaCl - to observe the effect on osmosis in carrots

Carrots Disks - to weigh carrot mass in

Beakers - to soak carrots in

Goggles - to protect eyes

Diagram

Method

First of all me and my group gathered all the equipment listed under
the heading apparatus. We then placed four pieces of carrots in six
different discs, the carrots were approximately of the same size. Then
I weighed each disc and recorded the mass, I also labelled the discs
of its masses.

Then I had to produce to following concentrations of NaCl solution 0M
(pure water), 0.25M, 0.5M, 1M, 1.5M, and 2M. I already had 1M and 2M
of NaCl solution so in order to get the other concentrations I added
water to the 1M and 2M concentrations of NaCl solution. I used a
measuring cylinder and dropper pipette to do this accurately.

Following this I poured the concentrations and distilled water into
six different beakers and dropped the six sets of carrots in recording
the mass of the carrots on the beakers I dropped them in. The Carrots
were all dropped in at the same time to keep the experiment fair.

After a day of soaking I took the carrots out at the same time and
dabbed them with paper towels to take of any excess external water and
put them in the same discs I previously weighed them in. Then I
reweighed the discs and recorded the masses.

Results Table

Concentration of NaCl solution

0M Pure Water

0.25M

0.5M

1M

1.5M

2M

Mass at start (g)

5.76

6.17

4.54

4.56

4.93

4.75

Mass at end (g)

6.1

6.29

3.93

4.08

4.43

4.4

Change in mass (g)

0.34

0.12

-0.61

-0.48

-0.5

-0.35

Percentage change in mass (%)

5.9%

1.9%

-13.4%

-10.5%

-10.1%

-7.4%

Start: End ratio

0.94

0.98

1.16

1.12

1.11

1.08

Observations

I have observed that in distilled water the carrots had a mass
increase of 0.34g indicating osmosis took place. In the 0.25M NaCl
solution the carrots had a mass increase of 0.12g and in the 0.5M
solution there was a mass decrease of 0.61g, in the 1M solution there
was a mass decrease of 0.48g, in the 1.5M solution there was a mass
decrease of 0.5g and finally in the 2M solution there was a mass
decrease of 0.35g. So I observed osmosis in all cases.

Conclusion

The results I got from my experiment were not what I had expected
because they did not agree to my prediction. The reason for this was
because of two factors I have thought of. The first was the mass; if
one group of carrots weighed more than another group they could have a
different amount of NaCl molecules and water molecules in the cells.
So this might have been the reason to why the mass of the carrots did
not decrease more as the concentration increased.

But looking at 0M which had carrots of a mass 5.76g and looking at
0.25M which had carrots of a mass 6.17g, the mass after the socking
did decrease more as the concentration increased. The mass of the 0M
carrots after soaking was 0.34g and the mass of the 0.25M carrots
after soaking had a mass of 0.12g, So the factor of mass of carrots
were not the reason my predictions were wrong because as the
concentration increased between 0M to 0.25M the mass did decrease
more.

The other factor which could have distorted my results was the
concentration gradient. The higher the concentration gradient, the
faster the rate of diffusion. This must have been the reason my change
in mass did not decrease as the concentration increased.

Looking at 0M, 0.25M and 0.5M the change in mass did decrease (0.24g,
0.12g, -0.61g) as the concentration increased. This was because the
concentration gradient was high allowing diffusion of water through
the permeable membranes take place faster. So in the time of soaking
allowed diffusion took place quick enough to support my prediction.

But for the 1M, 1.5M and 2M solutions one day was not enough time for
the mass of the carrots to decrease enough to support my prediction.
The reason for this was the concentration gradient was low allowing
diffusion of water to take place slowly so this is why at 1M my change
of mass in the carrots stopped decreasing more when I increased
concentration of solution. The change of mass in the carrots in the 1M
solution should have been higher than the change of mass in the
carrots in the 0.5M solution, which was -0.61g. But instead the change
of mass was -0.48g.

How ever in 1.5M the change in mass was lower than the change in mass
in the carrots in the 1M solution. The change in mass for 1.5M was
0.5g. But this was only an increase of mass decrease by 0.2g so this
was not enough evidence to suggest my results were not distorted by
the concentration gradient.

But again in the 2M solution which had the lowest concentration
gradient a more mass decrease was not observed. The mass change of the
carrots in the 2M solution was -0.35g.

How ever my other prediction, which was carrots in solutions below 1M
would have a mass increase and carrots in solutions 1M or above would
have a mass decrease was right to some extent. Only carrots in 0.5M
solution proved that prediction wrong because there was a mass
decrease when I expected a mass increase. But osmosis did take place
to all cases, so part of my prediction was correct. I know osmosis did
take place in all cases by looking at the start to end ratio. When the
start to end ratio is 1.0 this is only when it means osmosis did not
take place because there is equal number of water particles in the
solution and cell. But none of my start to end ratios displayed the
figure 1.0 they displayed 0.94, 0.98, 1.16, 1.12, 1.11 and 1.08. My
results suggest that the salt concentration inside the carrots is
between 0.25M and 0.5M.

Evaluation

Participating in this project has given me some very new extraordinary
skills, which I will find beneficial in the future. The theoretical
side as well as the practical side of this project did not stress me
in anyway, in fact it was a very easy to perform in. In the
theoretical side I was able to understand very well and I was able to
perform the experiment very easily in the practical side. But I did
have one trouble performing the experiment fairly and explaining to
what extent my predictions supported my results, quite difficult.

The reason to why I was unable to get my results to support my
prediction was down to one factor, which was the concentration
gradient.

At a low concentration of NaCl (e.g. 0molars NaCl) there is a much
higher concentration gradient. Because the concentration gradient is
higher, this means that there are many more particles of water in the
solution then there are in the carrots. This cause diffusion of water
through a partially permeable membrane to take place faster. So this
was the reason I was able to support my prediction in the results
table when the concentration increased form 0M to 0.5M. The reason to
this was they had a low concentration gradient. But then the
concentration was increased to 1M to 2M and the mass decrease did not
increase as concentration increased. The reason to this was they were
high concentrations and at high concentrations the concentration
gradient was low. This means there are less water particles in the
NaCl allowing diffusion of water through a partially permeable
membrane to take place slower.

So the time given for the carrots in those concentrations was not
enough time for the change in mass to have a more decrease as the
concentration increased. To improve this experiment and make it
support my predictions I could have keep the carrots soaking for a
longer period of time letting the experiment take place properly.

I also can try to make the experiment fair by making sure the surface
areas of the carrots and mass is exactly the same. If one carrot has a
bigger surface area then another, it has a larger space for which
osmosis can take place. If one carrot weighs more then another then it
could have a different amount of NaCL or water molecules in the cells.
I can avoid this by accurately cutting the pieces and checking masses
of carrots before using in experiment. I also could have made some
errors in making up the salt solutions and for more accurate
measurements of volumes of solutions volumetric pipettes are more
precise.

Another factor that could have affected my experiment was the fact
that each different type of carrot may have a different NaCl content;
and the same type of carrot may have different NaCL content. To
prevent this affecting my experiment I used the same carrot, although
this did not completely stop the problem. Maybe the outside of the
carrot has a higher amount of NaCl then the inside. So maybe if I was
to do the experiment again I will uses pieces only form a certain
layer of the carrot.

I can improve my method also by instead of using six sets of four
carrots I can use one carrot each time for each concentration of NaCl
and perform each experiment several times and work out the average
change in mass for each concentration and maybe this would help my
results to support my prediction. Also it is very possible for me to
try different vegetables and different solutions like potatoes,
raisins and sugar solutions. The solutions could have a wider range of
concentration of salt, beyond 2M and perhaps 0.75M, 1.25M, 1.75M
between the ranges of concentrations I used. All these changes would
just help to widen my investigation and help to support my prediction.

Also it is very important to pat dry the carrots gently especially
when left soaking in the weak solutions as the carrots are turgid and
swollen with water. In this experiment being precise with mass
measurements on the top pan balance is of great importance for
accurate results.

Overall I must say I am satisfied and have enjoyed this project
because for my predictions because I was able the give a scientific
explanation to why they have gone wrong. Also I have stated many
procedures how to improve my experiment, to avoid my predictions,
going wrong. I have also stated to how expand the experiment to
provide additional relevant evidence to support my predictions
further.

How to Cite this Page

MLA Citation:
"Osmosis in Carrots." 123HelpMe.com. 22 Dec 2014
    <http://www.123HelpMe.com/view.asp?id=148079>.




Related Searches





Important Note: If you'd like to save a copy of the paper on your computer, you can COPY and PASTE it into your word processor. Please, follow these steps to do that in Windows:

1. Select the text of the paper with the mouse and press Ctrl+C.
2. Open your word processor and press Ctrl+V.

Company's Liability

123HelpMe.com (the "Web Site") is produced by the "Company". The contents of this Web Site, such as text, graphics, images, audio, video and all other material ("Material"), are protected by copyright under both United States and foreign laws. The Company makes no representations about the accuracy, reliability, completeness, or timeliness of the Material or about the results to be obtained from using the Material. You expressly agree that any use of the Material is entirely at your own risk. Most of the Material on the Web Site is provided and maintained by third parties. This third party Material may not be screened by the Company prior to its inclusion on the Web Site. You expressly agree that the Company is not liable or responsible for any defamatory, offensive, or illegal conduct of other subscribers or third parties.

The Materials are provided on an as-is basis without warranty express or implied. The Company and its suppliers and affiliates disclaim all warranties, including the warranty of non-infringement of proprietary or third party rights, and the warranty of fitness for a particular purpose. The Company and its suppliers make no warranties as to the accuracy, reliability, completeness, or timeliness of the material, services, text, graphics and links.

For a complete statement of the Terms of Service, please see our website. By obtaining these materials you agree to abide by the terms herein, by our Terms of Service as posted on the website and any and all alterations, revisions and amendments thereto.



Return to 123HelpMe.com

Copyright © 2000-2014 123HelpMe.com. All rights reserved. Terms of Service