question_answer 112)

  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.

Answer:

                  This phenomenon is called endo osmosis, i.e., movement of water inside the raisin and shown with the help of diagram as The process of osmosis is of immense biological as well as industrial important. It is evident from the following examples.                                           (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 addition of salt. (iii) Preservation of fruits against bacterial action by adding sugar. Bacterium in canned fruit loses water through the process of osmosis and become inactive,                        (iv) Reverse - osmosis is used in desalination of water.