Osmosis is defined as the motion of H2O molecules through a semi- permeable membrane from an country of high concentration to an country of low concentration until a province of equilibrium is reached. Equilibrium is reached one time adequate H2O has moved to equilibrate the solute concentration on both sides of the membrane. Semi-permeable membranes allow little molecules such as H2O and O to go through it but big molecules such as proteins are prevented from traveling through it as it is merely partly permeable. Osmosis occurs across a partly permeable membrane whenever there is a difference between the H2O concentrations on the two sides of the membrane. When this happens to the cells they will either go bombastic if H2O flows into them, or flaccid if H2O flows out of them.
In this diagram the membrane separates pure H2O from a solution of saccharose and H2O. The membrane is semi permeable, H2O molecules can traverse it but the sucrose molecules are excessively big. The H2O solution will travel from a lower concentration of solutes to one with a higher concentration of solutes. A solution with pure solutes has more molecules that are free to travel approximately and follow their concentration gradient across the membrane ; as a consequence there will be net motion of H2O across this membrane from left to compensate ( shown by the xanthous pointers on diagram above ) .
Sugar solution has a low H2O potency ( non many H2O molecules ) .The H2O potency in the solution would be lower than that in the murphy cell so the net motion of H2O will travel out of the murphy through its membrane into the sugar solution and so the murphy ‘s mass will diminish. The opposite happens in H2O where the H2O potency is much higher than in the murphy ( about 0 ) . Here the net motion of H2O will travel into the murphy in order to making equilibrium and so the weight of the murphy additions.
To look into the consequence of changing concentration of a certain sugar solution on the sum of osmotic activity between the solution and two veggies ( murphy and sweet murphy ) of the same mass. To look into if the extra glucose in sweet murphy has an consequence on its mass compared to the normal murphy.
Before I start to transport out an experiment to look into my purpose, I am traveling to carry on a simple experiment to verify my cognition of osmosis. Making this experiment will besides assist me to better my chief experiment.
Plan: For my preliminary experiment I will be utilizing three different solutions: sugar solution, pure H2O, a solution consisting of 50 % H2O and 50 % sugar solution. I will besides be utilizing potato french friess which are all equal in mass. A cork bore bit will be used to cut out 3 murphy cylinders, the mass of the murphy cylinders will be Measured to do certain that they are equal in weight. Then the mass of each of the murphy bit will be recorded. Following 3 mensurating tubings will be placed on a trial tubing rack. Using a measurement cylinder tube 20ml of H2O, sugar solution and the solution consisting of 50 % H2O and 50 % sugar solution will be measured out and set into three different trial tubing. In order to avoid any blend up ‘s each trial tubing will be clearly labelled. One murphy bit will be placed in each solution and left for half an hr. Afterwards the murphies will be taken out of the solutions and their multitudes will be measured and recorded.
Get downing mass ( g )
Mass after ( g )
Difference ( g )
100 % Water
+ 6 %
50 % Water and 50 % sugar
100 % Sugar
From the consequences that I have obtained, I can see a negative correlativity between the concentration of the sugar in the solution and the mass of the murphy bit at the terminal of the experiment. While the solution incorporating 100 % sugar decreased in mass by 0.11g and the solution incorporating 50 % sugar decreased in mass by 0.03g, the solution that contained 0 % sugar increased in mass by 0.07g. This shows that in the two solutions incorporating sugar the mass decreased because H2O molecules moved out of the murphy french friess into the solution. The opposite happened with the H2O solution ; H2O moved from the solution into the murphy bit.
Overall I was please with the consequences as they agreed with what I have already learned about osmosis. The consequences that I got besides showed tendencies that could subsequently be expanded in my chief e experiment.
Over all my preliminary experiment was a success and the consequences I obtained were precise and utile. However for my chief experiment I am traveling to do some betterments so that I can acquire the best possible consequences. First I am traveling to experiment with sweet potato french friess every bit good as murphy french friess because I would wish to look into if the extra glucose in the sweet murphy has an consequence on its mass. In add-on I am traveling to be utilizing a wider choice of sugar concentrations in order to roll up a larger measure of accurate consequences. I am traveling to utilize H2O and 4 other concentrations. This will enable me to compose a decision that is more accurate. In my preliminary experiment I merely did the experiment one time. I am traveling to reiterate my chief experiment three times, by making so I will derive more assurance in my consequences as they will be more dependable. By reiterating the experiment I will be able to place any anomalousnesss. Further more in my preliminary experiment I could non take the murphy french friess out of the solutions at the same clip. I besides encountered this job when seting the murphy french friess into the solutions. For my chief experiment I am traveling to get the better of this job by inquiring a few of my associates to assist me set the murphy french friess into the solution and take them out at the same clip. This will do my consequences more accurate and just.
I predict that for the murphy bit in H2O the mass will increase because H2O has a higher H2O potency than the murphy bit so H2O molecules will travel from the H2O into the murphy bit, doing it to increase in weight. The opposite happens with sugar solution because sugar solution has low H2O potency so H2O molecules will travel out of the murphy bit into the sugar solution. Therefore I predict that as the concentration of sugar in the solution increases the mass of the murphy cylinders will diminish. I would anticipate Sweet murphies to hold a lower H2O potency ( non many H2O molecule ) than normal murphies, because they are ‘sweet ‘ and hence must hold contain sugar. Hence for the sweet potato french friess I predict that at foremost the mass of the sweet murphy will increase but, as the concentration of sugar in the solution increases past the isosmotic point the mass of the murphy cylinders will diminish.
I predict that the graphs for the both the veggies will be similar.My anticipation can be demonstrated in the undermentioned graphs:
While I carry out this experiment, it is of import to see safety. Lack of safety in scientific discipline labs can non merely jeopardize me and my fellow category couples but can besides bring forth hapless and useless consequences. Following safety processs protects the lab, its people and the environment. Safe labs besides help bring forth effectual consequences. These are the safety measures I took:
All bags were kept good off from the country of work so that no tracts were being obstructed and the hazard of person tripping over was reduced.
All stools were tucked in under the tabular arraies in order to avoid a passer-by tripping over. Both this point and the one above can turn out to be fatal if the victim is keeping any unsafe equipment e.g. Scalpel, acerb etc. It can besides do spills.
Loose hair was tied up ; arms rolled up and caput scarf ‘s tucked off. Hair and vesture can acquire in the manner while working. It is besides unsafe
and can do spills, ruin experiments and even potentially harm me or others around me.
No earpieces, scarves or jewelry was worn as these can catch on equipment and cause spill or amendss.
Safely spectacless were worn at all times to guarantee our eyes were protected from and possible danger.
It was made certain that the work country was clear of any unneeded points such as reading books and booklets as these can acquire in the manner and cause accidents.
Working softly and carefully. Talking unnecessarily can be a distraction to me and others around me, when distracted it is easier to do errors that can non merely be unsafe but can besides impact my consequences.
Chipped and cracked glass wear was non used as this could interrupt more easy if handled a batch and make a muss. It can besides do hurts. Extreme attention was taken when utilizing equipment made of glass e.g. trial tubing.
Eating and imbibing in the labs is forbidden as the nutrient may come into contact with some harmful substance. This could be insecure for the consumer.
When utilizing stab a non-slip surface was used to cut on so that no 1 was injured.
After completing the experiments, I washed my custodies because my custodies could be contaminated with chemicals, even if they were non used by me.
All equipment was safely stored off after usage as go forthing unwanted equipment about can do accidents and acquire in the manner.
Accuracy and Dependability
There are the undertakings, which I undertook to guarantee dependable and precise consequences were produced.
To extinguish all possibilities of defective mistakes ; I repeated my experiment three times. In add-on, I had no less than 5 different concentrations, so I obtained equal consequences.
In order to increase the dependability of the consequences, I found more precise values of mass by utilizing an Electronic balance.
When mensurating the murphy and sweet murphy cylinders, I waited for at least 10 seconds to guarantee that the figure displayed on the digital graduated table was non flicking.
If any readings seemed anomalous, I took an extra reading merely to be certain.
I collaboratively, with the aid of 3 other members, measured the mass of the murphy and sweet murphy cylinders separately. This gave more dependable consequences as the multitudes of all the murphy cylinders were measured about the same clip.
I used pieces from the same murphy and sweet murphy for each of the 5 pieces in each trial.
I used precisely the same method for each trial to do the comparing much more dependable.
Goggless: – These were worn for safety grounds to avoid anything from coming into contact with the eyes.
Electronic balance: – I used this setup to mensurate the mass of the murphy and sweet murphy cylinders before and after they were put in their molar solutions. Electronic balances are besides more accurate that normal balances.
Test tubing: – These were used to keep the molar solution and the potato/ sweet murphy cylinder for each molar solution for every experiment and trial.
Healthy murphies: – This was one of two chief veggies used for the experiment.
Healthy Sweet murphies: – This is the 2nd veggie that was used for the experiment. This veggie was chiefly used so that I could look into if the extra glucose in sweet murphy has an consequence on its mass compared to the normal murphy.
Choping board: – This was used to cut the murphy cylinders on. Using this non merely kept the lad neat and tidy but besides prevented hurts as it is a non-slip surface.
Knife: This was used to cut the murphy cylinders if the mass was excessively much.
Timer/stop ticker: – This was used to clip the experiment. It is besides more accurate than utilizing a clock.
Paper towels: – These were used to chuck the murphies dry before being measured at the terminal of the experiment. If the murphies were measured without being dried foremost so the extra liquid on the murphy can do it to increase the mass.
Test tubing rack: – This was used to keep the trial tubing.
Sugar solutions ( 1 grinder and 2 grinder ) : – These solutions were really important for the experiment, as they, with the murphy cylinders, caused osmosis to happen.
Water: – Used to do certain concentrations of sugar solution.
Cork bore bit: – To cut the same form murphy pieces.
Measuring cylinder: – To mensurate out certain sums of H2O and sugar solution.
Labels: -To labels the trial tubes so it is easier to place the contents inside each trial tubing.
In this probe I had three different variables:
The independent variable – This is a factor that can be changed.
The dependent variable – What you step and what is affected in the experiment.
Fixed variable- The factors you keep the same.
The independent variables:
I changed the concentration of the sugar solution. I used ; H2O, 0.5 grinder sugar solution,1 grinder sugar solution, 1.5 grinder sugar solution and eventually 2 molar sugar solution. I besides changed the types of murphy used ( sweet murphy and normal murphy )
The dependent variables:
I measured the mass of the Sweet murphies and murphies before puting in the solutions and after. This is something that is affected during the class of the experiment.
All the murphies and Sweet murphies I used were that same in mass ( 0.64g ) . The volume of each solution in each trial tubing was besides the same ( 20ml ) . In add-on I kept the murphy and Sweet murphies in the solutions for the same length of clip ( 40 proceedingss )
It is merely by transporting out a just trial that I can be certain that it is what I have changed ( independent variable ) that is impacting what I measured ( dependent variable ) .
In order to acquire accurate consequences I needed to guarantee that my trial was just.
Therefore in this experiment I controlled:
The volume of solution in each beaker
The mass of the murphies and Sweet murphies at the start of the experiment
The length of clip the murphies and Sweet murphies were left in the solution.
I ensured that the murphy and sweet murphy cylinders were put in the solutions and taken out of the solutions at the same clip.
First acquire 2 trial tubing racks and topographic point 5 trial tubings on each rack label one trial tubing rack “ sweet murphy ” and label the other rack “ murphy ”
Get some gluey labels and label each trial tubing with the solution it is traveling to incorporate ( H2O, 0.5 grinder, 1 grinder, 1.5 grinder, 2 grinder, ) . Make this for the trial tubing on both racks.
Using the measurement cylinder step out 20ml of 1 molar sugar and pour into the trial tubing labelled “ 1 grinder ” .
Then step out 20 milliliter of 2 molar sugar solution and pour in to the trial tubing marked “ 2 grinder ” .
After step out 20 milliliters of H2O and pour in to the trial tubing marked “ H2O ”
Following make the different concentrations of sugar solution. ( 1 grinder and 2 grinder are already provided ) .
-To make 0.5 grinder: utilize the measurement cylinder to mensurate out 5 milliliter of 1 molar sugar solution and 15ml of H2O. Mix these together and pour into the trial tubing labelled 0.5 grinder.
To do 1.5 grinder: utilize the measurement cylinder to mensurate out 15 milliliter of 1 molar sugar solution and 5ml of H2O. Mix these together and pour into the trial tubing labelled 1.5 grinder.
( Make the above 5 points for all the trial tubing on both racks. By the terminal of point 6 you should hold two trial tubing racks one labelled “ murphy ” and the other labelled “ sweet murphy ” , each rack must keep 5 trial tubings, each trial tubing must be labelled with the solution that it holds e.g. H2O, 1 molaraˆ¦etc. )
Afterwards, acquire a healthy murphy ; do certain the tegument is peeled. Using the cork bore bit cut out 5 murphy cylinders.
Using the electronic balance, weigh all the murphy cylinders. They should all weigh around 0.64g. If they do n’t so change them consequently utilizing a chopping bored and knife and topographic point to a side. Remember to enter the multitudes.
Subsequently, acquire a healthy Sweet murphy. Once once more do certain the tegument has been peeled. Using the cork bore bit cut out 5 murphy cylinders.
Using the electronic balance, weigh all the sweet murphy cylinders. They should all weigh around 0.64g. If they do n’t so change them consequently utilizing a knife and a chopping bored. Remember to enter the multitudes.
Then both the sweet murphy and normal murphy must be put in to the solutions, each trial tubing must incorporate either 1 murphy cylinder or 1 sweet murphy cylinder. Make certain all the cylinders of murphies and Sweet murphies are dropped into the solutions at the same clip ( inquire aid from schoolmates if needed ) . The timer should besides be started now.
( Leave the solutions in this province for 4o min )
After 40 min, the murphies and Sweet murphies must be removed from their solutions. Again, they should all be taken out at the same clip ( once more inquire for aid if needed ) . Make certain the murphy cylinders do non acquire assorted up ; guarantee that you know which cylinder came from which solution.
Dry each cylinder and step it ‘s mass one by one. Ensure that the multitudes are recorded one time once more.
( All the above was repeated 2 more times to increase the dependability in my consequences )
During the experiment I noticed that some of the murphy and sweet murphy cylinders in higher concentrations of sugar started to drift. In the 1.5 and 2 molar sugar solutions the murphy has higher H2O potency that the sugar solution so H2O molecules from the murphy cells would hold moved into the sugar solution, this made the murphy cylinders float to the top of the solution instead than remain at the underside of the beaker because it became lighter. This happened after about 10 -15 proceedingss. After about 20 proceedingss the murphy cell in 1 molar sugar solution started to drift every bit good. This is because as the murphy cells are losing H2O molecules, they bit by bit become lighter. The murphy in H2O did non float, nor were there any seeable alterations. All the above applies to both the sweet murphy and normal murphy.
A difference I noticed between the two types of murphy was that while the murphy in the 0.5 molar solution floated a somewhat, the sweet murphy in the 0.5 molar solution did non drift at all, it remained still, similar to the murphy cylinder ‘s in H2O. I besides noticed that the murphy cylinders floated higher than the sweet murphy cylinders.
Below are the computations I did to work our assorted facet of the consequences:
Percentage alteration in mass = Change in mass ten 100
Averages = All three multitudes in one class added
The figure of different multitudes
Change in mass = New Mass – Original Mass
Both the graphs show negative correlativity between the concentration of the sugar in the solution and the mass of the murphy bit at the terminal of the experiment. It is clear from the graphs that osmosis has taken topographic point.
Potato: For the murphy cylinder put in H2O ( 0 % sugar ) the murphies mass has increased 21.87 % signifier 0.64 gms to 0.73 gms, this shows that because H2O has a higher H2O potency than the murphy cylinder, H2O molecules have moved from the H2O into the murphy doing its weight to increase. When this happens the cell becomes bombastic ( difficult and conceited ) .For the murphies in all the other solutions ( 1 grinder, 0.5 grinder, 1.5 grinder and 2 grinder ) the mass of the murphies decreased. This shows that H2O molecules have moved out of the murphy cell into the sugar solutions. When a cell loses H2O in such a manner the cell go flaccid, which is the antonym of turgid.
Sweet murphy: For the sweet murphy cylinder that was placed in H2O the mass increased as expected. This happened because H2O moved from the solution into the sweet murphy.
For all the other molar concentrations, except the sweet murphy placed in 0.5 molar solution, the alterations were the same as for the murphy. For the sweet murphy placed in 0.5 molar solution the mass increased from 0.64 gms to 0.65 gms. There was a 0.01 gm addition in the mass of the sweet murphy by the terminal of the experiment. This suggests that my anticipation was right: – I expected Sweet murphies to hold a lower H2O potency than normal murphies because they are ‘sweet ‘ and hence must hold contain sugar. Hence for the sweet potato french friess I predicted that at first the mass of the sweet murphy will increase but, as the concentration of sugar in the solution increases past the isosmotic point the mass of the murphy cylinders will diminish. There was a 0.01 gm addition in the mass of the sweet murphy by the terminal of the experiment. 0.01g is highly close to 0g. On the graph, if you look at this point, it is clear that the scope saloon is in between 1.56 % and 0 % . If there had been a 0 % alteration in mass, it would intend that a province of equilibrium had been reached. This is a point where the concentration of H2O inside the sweet murphy cell is the same as the concentration of H2O in the solution which the Sweet murphy is in. my consequences imply that the ground the mass of the sweet murphy in the 0.5 molar sugar solution increased in because the H2O potency of the sweet murphy was somewhat lower than that of the H2O. As a consequence H2O molecules moved in to the sweet murphy cell. The sweet murphy in 1.5 molar sugar solution decreased weight because the concentration of sugar in the solution had increased passed the isosmotic point ( equilibrium ) .
My graphs show that osmosis has taken topographic point. There was a negative correlativity between the concentration of sugar in the solution and the mass of the murphy or sweet murphy cell at the terminal of the experiment. Over all the consequences that I obtained have answered my purpose ; changing the concentration of the sugar does hold an affect on the mass of the veggie and the extra sugar in sweet murphy does hold an consequence on its mass when compared with normal murphies.
With the consequences I have obtained I can reason that the higher the concentration of sugar in the solution, the more mass the murphy looses. The graph besides shows that the antonym happened when the concentration of H2O in the solution is higher. So I can reason this by stating: the higher that concentration of H2O in the solution the more mass the murphy additions. This applies for both the murphy and sweet murphy. However because of the extra sugar in the sweet murphy, the mass of the sweet murphy will merely diminish after the concentration of sugar in the solution increases past the isosmotic point ( point of equilibrium ) .
To do full sense of the decision, a review on osmosis and the affect on cells are required. When there is a high concentration of H2O in the solution and a works cell with low concentration of H2O into H2O, the H2O would travel into the works cell by osmosis. Osmosis is defined as the motion of H2O molecules through a semi- permeable membrane from an country of high concentration to an country of low concentration until a province of equilibrium is reached. Equilibrium is reached one time adequate H2O has moved to equilibrate the solute concentration on both sides of the membrane. Osmosis occurs across a partly permeable membrane whenever there is a difference between the H2O concentrations on the two sides of the membrane. When this happens to the cells they will either go bombastic if H2O flows into them, or flaccid if H2O flows out of them.
The consequences that I have obtained in this experiment support the anticipation that I made utilizing scientific theory and my preliminary experiment.
Overall I was please with the consequences that I gained as they agreed with what I have already learned about osmosis. I believe I have gained dependable consequences, which supports the scientific theory. After doing alterations to my chief experiment from the preliminary experiment I faced no troubles. The equipment that I used was suited, I managed to roll up equal informations and the probe that I organised was effectual, as can be seen from my consequences. I was able to acquire adequate consequences to come to a strong and explanative decision. I believe that my consequences were moderately accurate as I did the experiment 3 times and found that the perennial consequences were largely really near together. With these consequences I was able to build two, really accurate and enlightening graphs.
My consequences were free from any major anomalousnesss that did non suit the regular form. However there were one or two really minor anomalousnesss that could hold been caused by the followers:
Some restrictions or experimental mistakes could hold occurred during the probe, which I did non gain and could hold led to some misreckonings in my consequences. The chief restriction could hold been the alteration in temperature of the room during the experiment. High temperatures could hold altered the rate at which osmosis takes topographic point. Another possible job in the probe may be fiddling, as the probe was carried out in a lab which is in changeless usage. This could hold resulted in pupils playing with the setup, which could hold affected the out semen of my consequences. Besides when drying the murphy french friess after the allotted clip it was inevitable that they would hold extra H2O on them, and so we dabbed them with paper towels to take it. However, in making this we could hold removed H2O that was non extra, and altered our consequences.
To do my probe more dependable and accurate I could do some betterments. First I could utilize a wider and more precise fury of sugar concentrations. If I did this I would hold a wider scope of consequences to work with so it would be more accurate and I would be able to come to a more unafraid decision. Another betterment I would do if reiterating the experiment is to dry all the murphy cylinders the same. I used paper towels to dry the murphy cylinders, which caused fluctuation between the murphies as amount where dried more thorough and for longer than others which affects their mass, and those potato cylinders that have non been dried every bit much as others will hold more extra H2O and hence a greater mass. In the hereafter I would develop a method to dry the murphies in a manner that is just.
Further probes may be to look into utilizing lengths or forms of murphies, to see affect of osmosis upon them. I could make a comparative survey, where I see the effects of osmosis on murphies which have been altered to make specific genteelness, e.g. turn in a hot clime, etc. I could make a survey into surface country or the effects of temperature upon osmosis, to place the best temperature in which osmosis occurs. I could besides look into the affects of osmosis on different veggies such as eggplant, Brassica rapa, carrots.