Question

Define reverse osmosis. Name one SPM which can be used in the process of reverse osmosis.

Answer 1

Reverse osmosis is a process in which solvent moves from a solution with higher concentration to a solution with lower concentration through a semipermeable membrane, but this process occurs when external pressure is applied that exceeds the osmotic pressure. This reverses the natural osmotic flow. An example of a semi-permeable membrane (SPM) used in reverse osmosis is cellulose acetate.

Answer 2

When red blood cells (RBCs) are placed in a 0.5\% NaCl solution, which is hypotonic relative to the intracellular fluid, water will move into the RBCs due to osmosis. This causes the cells to swell as water enters. If too much water enters, the RBCs may burst, a process known as hemolysis.

Answer 3

Osmotic pressure is directly proportional to the number of solute particles in solution. Since KCl dissociates into two ions (K\(^+\) and Cl\(^-\)) in solution, a 1 M KCl solution will have a higher osmotic pressure than a 1 M urea solution, which does not dissociate into ions. Therefore, the 1 M KCl solution will have a higher osmotic pressure.

Answer 4

Osmotic pressure is a colligative property because it depends only on the number of solute particles in a solution, not on their nature or identity. The greater the number of solute particles, the higher the osmotic pressure, regardless of whether the solute is ionic or non-ionic.