Neither liquid solvent, nor solution nor solute molecules pass through SPM. Only vapours pass through SPM. When an aqueous solution and water are separated by SPM, vapours of water molecules from water pass into solution through SPM. It is because water has higher vapour pressure than the solution. Infact, osmosis takes place from a solution of high vapour pressure to a solution of low vapour pressure. When two solutions are separated by SPM, the solution of lower molar concentration has high vapour pressure. Therefore, osmosis takes place from a solution of lower molar concentration to a solution of higher molar concentration. Goat's bladder, egg membrane, wall of living cells, parchment, cellophane etc. are common SPM. But these are not perfectly semi-permeable and are weak too. Artificially prepared cupric ferrocyanide Cu2 [Fe(CN)6] is the best SPM.
i. ASSERTION – Osmotic pressure is a colligative property
REASON- Osmotic pressure is directly proportional to molarity
a. Both assertion and reason are true, and reason is the correct explanation of assertion.
b. Both assertion and reason are true, but reason is not the correct explanation of assertion.
c. Assertion is true but reason is false
d. Both assertion and reason are false.
ii. ASSERTION - If the blood cells are placed in pure water, they will swell and burst
REASON- Due to osmosis the movement of water molecules into the cell dilutes the salt content.
a). Both assertion and reason are true, and reason is the correct explanation of assertion.
b). Both assertion and reason are true, but reason is not the correct explanation of assertion.
iii. ASSERTION- Osmotic pressure is numerically equivalent to the osmotic potential.
REASON- Osmotic pressure is the negative pressure applied while the osmotic potential is positive.
a. Both assertion and reason are true, and reason is the correct explanation of assertion.
b. Both assertion and reason are true, but reason is not the correct explanation of assertion.
c. Assertion is true but reason is false.
d. Both assertion and reason are false
c). Assertion is true but reason is false.
d). Both assertion and reason are false.
iv. ASSERTION- 1 M solution of KCl has greater osmotic pressure than 1 M solution of glucose at the same pressure.
REASON- In solution, KCl dissociates to produce more number of particles
a. Both assertion and reason are true, and reason is the correct explanation of assertion.
b. Both assertion and reason are true, but reason is not the correct explanation of assertion.
c. Assertion is true but reason is false.
d. Both assertion and reason are false.
