When kept in water, raisin swells in size. Name and explain the phenomenon involved with the help of a diagram. Give three applications of the phenomenon.

Explanation

When kept in water, raisen swells in size. It is because of a phenomenon known as .Osmosis. The process is diagram matically represented in figure below. In this process a solution is separated from solvent by a semi permeable membrane which allows the passage of solvent molecules but does not permit solute particles to pass through.

Osmosis is the process of flow of solvent molecules from pure solvent to the solution through semi permeable membrane. Three applications of osmosis are :
(i) Movement of water from soil into plant roots and subsequently into upper portion of the plant is partly due to osmosis.
(ii) Preservation of meat against bacterial action by adding salt.
(iii) Preservation of fruits against bacterial action by adding sugar. Bacterium in canned fruit loses water through the process of osmosis, shrivels and dies.