Question

CaCO3 shell is carefully removed from two eggs by treatment with dil.HCl. One of the eggs is then placed in pure water while the other in a saturated solution of NaCl. What will be observed and why?

Answer 1

Salt concentration inside the egg is higher than water but less than saturated NaCl solution. So if the egg (after removing the outer shell) is placed in water, water will go inside through the semipermeable membrane (osmosis occurs) and egg will swells up. In salt solution osmosis will occur and flow of water is opposite direction , water will come out of the egg and egg will shrink in size.

OR Another way

After a few hours, it will be noticed that the egg placed in water swells and the one in salt solution shrinks.Equilibrium is being established in both cases.

1. In the first case, water diffuses through the skin, a semipermeable membrane, into the egg material, which swells.
2. In the second case, the concentration so the salt solution being higher than the egg, the material shrinks.

Thus, Osmosis equilibrium results, whenever there are two parts of solution, separated by a semipermeable membrane.