IntroductionOsmosis is a physical phenomenon in which water or solvent molecules move from dilute solution to a concentrated solution where both the solutions are separated by a semi-permeable membrane. In other words osmosis also can be defined as the movement of water molecules from its (water) higher concentration to its lower concentration through a semi-permeable membrane. In osmosis process movement of water molecules only occur between two deferentially concentrated solutions separated by a semi-permeable membrane. In plants or animals the cell membrane which separate two cells acts as semi-permeable membranes. Cell membrane or plasma membrane of plant cells and animal cells, egg's membrane, Goat's bladder membrane are the natural substance which act as semi-permeable membrane. Cellophane paper, Parchment paper, Viskins bag are the substances which act as semi-permeable membrane are artificial in nature.
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Aim of the ExperimentTo demonstrate Osmosis process by Thistle funnel and egg's membrane.
Requirements:-Beaker, Water, Sugar solution, Egg's membrane, an iron stand.
Demonstration of Osmosis process-(A) Experimental Setup and (B) Control Setup
Procedure for the experimentA wide mouthed thistle funnel with a narrow long stem was taken. Then an egg's membrane collected from an egg is tied tightly around the wide mouth of the funnel with the help of a thread or rubber band. Now dilute sugar solution is carefully poured into the stem of the funnel to a certain level. The wide mouth of the funnel containing sugar solution is now kept in a beaker with the help of an Iron stand. Now three fourths of the beaker is filled with plain water. A similar control setup also arranged but by taking plain water in the beaker and also plain water in Thistle Funnel. The apparatus are left undisturbed for 10 minutes and we observe the changes in the experimental setup as well as in control setup.
ResultAfter few hours we find the level of sugar solution increases from its initial level in the experimental setup while there is no change in the level of water in the stem of Thistle Funnel in the control setup. This observation clearly indicates the movement of water molecules occurred from the beaker into Thistle Funnel in the case of experimental setup while in the control setup that there is no movement of water molecules from beaker into Thistle Funnel through egg's membrane because both the solutions are of same concentration.
Questions and answers related to the experiment
Ans. There will be increase in the level of sugar solution in the stem of the Thistle Funnel because water molecules from beaker entered into it through the egg's membrane which is a semi-permeable membrane.
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Ans. By using a control setup we can clearly prove through that in osmosis process water molecules are only moving from a dilute solution to a concentrated solution through a semi-permeable membrane.
Ans. Parchment paper, Cellophane paper, Goat's bladder membrane.
Ans. Egg's membrane acts as a semi-permeable membrane in the above experiment. A semi-permeable membrane is a membrane which allows smaller particles like water molecules through it but prevents the movement of larger particles like sugar or salt particles.
Ans. The tonocity of solution kept in the Thistle funnel of experimental setup is Hypertonic solution. A solution which is more concentrated in nature when compared to the surrounding solution is known as Hypertonic solution.
The tonocity of solution kept in the Thistle funnel of control setup is Isotonic solution. A solution which is equal in concentration with surrounding solution is known as Isotonic solution.
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Here is a video of Osmosis experiment:-