15. The Fig. 1 and 2 show the apparatus used in an experiment to study Osmosis. Fig. 1 String Visking tubing salt solution Tap water Beginning (a) (i) Explain the results obtained at the end of the experiment. Fig. 2 At the end (3mks) (ii) State the function of the visking tubing in the experiment hence give its equivalent in plants. (2mks) (b) Explain why growing grass die after a few days when common salt is spread on it. (3mks) (c) State the advantages of the cell protoplasm being colloidal in nature. (2mk)