Question

difference between osmosis and diffusion how is osmotic pressure determined by Berkeley Hartley method

Answer 1

Both diffusion and osmosis are passive transport processes, which means they do not require any input of extra energy to occur. In both diffusion and osmosis, particles move from an higher concentration to one of lower concentration.

Diffusion can occur in any mixture, including one which includes a semipermeable membrane, while osmosis always occurs across a semipermeable membrane.

Answer 2

Osmosis:

            It is the diffusion of a solvent across a membrane from a region of lower concentration to a region of higher concentration.

Diffusion:

            It is the movement of a substance from an area of higher concentration to an area of lower concentration.

Many methods are applied for determining osmotic pressure but the most appropriate is Berkeley and Hartley method.

In this method, porcelain tube is used which is filled with solvent and solution is placed in a metallic jacket. Due to osmosis, when the solvent moves toward solution the capillary tube level will move downward. With the help of piston, external pressure on the solution is applied to keep capillary level stationary.

Record the reading. This is osmotic pressure.