CBSE Class 12 Chemistry Notes: Solutions – Some Important Concepts

• In a mixture of two solutions, the solution with lower osmotic pressure is hypotonic while solution with higher osmotic pressure is hypertonic.
• The outflow of fluid from the plant cells placed in a hypertonic solution is known a plasmolysis (shrinkage of plant cell).
• At freezing point solid and liquid are in equilibrium so, they have the same vapour pressure.
• When on cooling a solution to its freezing point, the crystals of solvent are separated first.
• Semi­permeable membrane is required in osmosis but not in diffusion.
• In diffusion a substance moves from a region of its higher concentration to regions of its lower concentration.
• In reverse osmosis, flow of solvent is from higher to lower concentration. For example, desalination of sea water.
• Copper Ferro cyanide [Cu₂Fe (CN) ₆] is a chemically prepared semi­permeable membrane.
• Plant and trees absorb water from soil by osmosis.
• Osmotic pressure is mainly calculated by Berkley and Hartley method.
• Townsend method is used to find the osmotic pressure of non-aqueous solution without using semipermeable membrane.
• 6% urea solutions and 0.1 M glucose solutions are iso­tonic.
• The mole fraction of the more volatile component is always greater in vapour phase than in solution phase (Konowaloff rule)

Class 12 Chemistry Solutions All Topics Notes Class 12 Chemistry All Chapters Notes