Question

The basis of reverse osmosis is _____________

(a) Osmotic pressure is greater than the hydrostatic pressure

(b) Osmotic pressure is equal to the hydrostatic pressure

(c) Hydrostatic pressure is greater than the osmotic pressure

(d) Osmotic pressure does not exist

I had been asked this question at a job interview.

My enquiry is from Reverse Osmosis topic in chapter Water and its Treatment of Engineering Chemistry II

Answer 1

Correct answer is (c) Hydrostatic pressure is greater than the osmotic pressure

To explain I would say: The basis of reverse osmosis is that the hydrostatic pressure is greater than osmotic pressure. It is a process by which a solvent passes through a porous membrane in the direction opposite to that for natural osmosis when subjected to a hydrostatic pressure greater than the osmotic pressure.