Study the phenomenon of osmosis

Materials Required

  • Two raw eggs
  • Dil. hydrochloric acid a salt (or sugar) solution of about 25% concentration in water - (dissolve about 25 g salt in 100 mL water)
  • Beakers
  • Petri dishes.  

 

The Procedure

Real Lab Procedure

  • Dissolve the two raw eggs by placing them in two separate beakers containing dil. HCl. Hydrochloric acid . 
  • Keep the two raw eggs in dil. HCl for about 4-5 hours. It forms some gaseous characteristics.  
  • Carefully drain off the acid from the beakers and wash the eggs thoroughly with water while they are still in the beakers. Repeat this process several times till all traces of acid are completely removed.   
  • Observe the de-shelled eggs.  
  • Fill one beaker containing one de-shelled egg with water and the other beaker with another de-shelled egg with the concentrated salt solution.   
  • Drop the eggs into each beaker with a help of a spoon.  
  • Leave the set up for about four hours and observe the two de-shelled eggs.  

  

Simulator Procedure

  • Drag and drop the first egg into the beaker containing dil. HCl.
  • Drag and drop another egg into the second beaker containing dil. HCl.
  • Corresponding to that, the movement of a clock will be shown along with the reaction in an egg dipped in dil. HCl. 
  • Observe the de-shelled egg after 4 hours.
  • Drag and drop both the deshelled egg into the third beaker containing normal water. 
  • Click on the next button.
  • Two beakers will be shown, one containing normal water and the other beaker containing salt solution.
  • Drag and drop the deshelled egg into each beaker containing water and salt solution.
  • Leave the beaker for 4 hours, and the movement of a clock will be shown. 
  • Click on the next button.
  • Zoomed image of egg in water and salt solution will appear.
  • Observe the changes in the de-shelled egg after 4 hours.
  • Click on the information (i) icon to see the inference. 
  • You can redo the experiment anytime by clicking on the ‘Reset’ button. 

 

Observation

  • The de-shelled egg when placed in water swells because the concentration of water molecules outside the egg is much higher than the concentration of water molecules inside the egg, as a result of which endosmosis takes place and water from the beaker enters the egg.  
  • Exosmosis takes place when the de-shelled egg is placed in a salt solution. The water comes out from the de-shelled egg into the salt solution. The loss of water results in the shrinkage of the egg.