International baccalaureate biology sl investigation_osmosis by felix dyrek
Felix Dyrek Biological Investigation: OsmosisIntroduction:The experiment was made in order to check how osmosis occurs in food when its placed indifferent types of solutions.In my case what was used were carrots and potatos.Research Question:How will different solutions affect the osmosis of carrots and potatos ?Hypothesis:When we put slices of carrots and potatos seperated in two different solutions like destilatedwater,vinigar, and water with 10% and 20% salt concentration,the carrots and potatoes will gainwater in the destilated water but they will loose it in the concentration of salt and the vingar.Theamount of it will stay the same.Hypothesis Explanation:The carrots and potatoes will gain water + mass because the concentration of water will have ahiger mass than in the cells of the slices.Its a hypotonic solution.In the waters which are saltconcentrated the slices will loose water + mass because the salt water is lower concentrated thanin the cells of the slices.It is a hypertonic solution.In the vinegar the concentration of water staysmore or less the same as the slices so its isotonic solution.Compounds:1 small potatoe1 carrot400 ml water100 ml 10% white vinegar30 gr salt
Variables:Dependentsolution in which the slices are put in %mass of the slices grindependentApparatus :4 beakers4 Petri dishes1 scale1 baguette1 cylinder volume1 timer1 knife1.We cut the potatoe and the carrots in small slices on the cutting board.Then weight out 12 grof potatoe slices and also 12 gr of carrots slices.In each of the four Petri dishes are 12 gr ofpotatoe and carrots.2.The next step is to prepare the solutions in which the carrots and potatoes will be dippedin.For one solution:The graduated cylinder we measure 90 mL of water and poud it into abeaker.Then we add 10 gr salt to it.The next step is to mix it with the baguette until the saltdissolves.The water we have now has a concentration of 10% salt.We repeat the step and useanother beaker where we are mixing 80 mL of water with 20 gr salt to recieve a 20% saltconventration.3.In the first Petri dish we fill 100ml destillated.In the second Petri dish we fill 100ml of vinegar.In the third we will 100ml of 10% concentrated salt water .In the fourth we fill 100ml of the 20% concentrated salt water.We let the potatoe and the carrot slices for 30 minutes soaking in the soluitons.
4.After 30 minutes we take the carrot and potato slices out of their Petri dishesThen weigh eachgroup, carrots and potatoes separately. Record these measurements, observing if their mass haseither increased or decreased.5.Design a chart and transfer your results onto that chart. Then draw a graph displaying yourresults.
Data Collection & Processing(raw data on attached paper)Solution [100mL] Vegetable Mass at Mass after 30 Observations start [g] minutes [g] Distilled water potato 12 13.1 Both vegetables became very stiff carrot 12 13.0 Salt water (10% potato 12 10.3 Both vegetables became soft & flexible concentration) carrot 12 11.3 Salt water (20% potato 12 10.2 Both vegetables more soft & flexible than concentration) vinegar carrot 12 10.4 Vinegar potato 12 11.6 Both vegetables very soft & flexible, wilted carrot 12 11.9Table 1: Results and observations of the experiment Graph1: Comparison between solutions and the mass of vegetables
Conclusion & EvaluationFrom these results, we can sum up that my hypothesis is accurate. In the distilled water, the massof the carrot and potato slices increased, making the distilled water a hypotonic solution. In thesalt water (both 10% and 20% concentration), the mass decreased, which means it was ahypertonic solution. The mass of the slices in the vinegar barely changed at all, but the mass didin fact decrease slightly, so the vinegar should be regarded as a hypertonic solution.However, in must be taken into consideration that this experiment couldve been carried out morecorrectly. It can be noticed that in the distilled water, the mass of the potato slices was 13.1g andthe carrot slices was 13.0g, which is a very small difference - but the potato slices were stillheavier. On the other hand, in the rest of the solutions, the carrot slices were heavier than theones of the potato after osmosis (see Table 1 and Graph 1). If we were to to base the finalconclusion on these results, then it would be that when it comes to gaining water during osmosis,potatoes gain more water than carrots, and when it comes to losing water, then carrots are morelikely to lose a greater amount of water. This could possibly have something to do with thedifferent structure, thickness and texture of each vegetable. Or it could mean an error occurredand the slices werent weighed correctly, which is more probable, as the conclusion isnt 100%clear.Nevertheless, osmosis definitely occurred in each of the samples, because it was also observedhow the slices of the potatoes and carrots changed their appearance and feel during theexperiment (see Table 1). The slices in the distilled water were very stiff and very hard to breakin half. In the vinegar, the slices stayed more or less the same, except that they were maybe a bitmore flexible than before they were placed in the vinegar. In the salt solutions, the potato andcarrot slices were noticeably more flexible than before they were put in the solutions – in thesolution with the 20% concentration of salt, the slices were so bendable that they were slightlywilted, and the edges had started to fold up. We can conclude that the general aim of theexperiment was reached, as the osmosis of carrot and potato slices in different solutions wassuccessfully observed.Felix Dyrek