2.14 describe experiments to investigate diffusion and osmosis using living and non-living systems

2.14 •diffusion in non-living systems: •add agar jelly to phenolphthalein and dilute sodium hydroxide, making the jelly pink        

                                                            •fill a beaker with dilute hydrochloric acid, add cut jelly cubes

                                                            •leave and they’ll turn colourless

           •osmosis in living systems: •cut up potato cylinders identically, and get beakers with different sugar solutions (one pure)

                                                       •measure the length, leave for half an hour, then remeasure

                                                       •ones that drew in water (pure water), will be longer than the ones in the concentrated sugar solution as they draw out the water

           •osmosis in non-living systems: •put a glass tube in the Visking tubing and use a wire to tie it (Visking tubing is a partially permeable membrane)

                                                              •pour some sugar solution down the glass tube into the

                                                               Visking tubing, and place it all in a beaker of pure water

                                                                        •measure where the solution comes up to on the tube

                                                              •leave it overnight, and measure where the liquid is in the glass tube

                                                              •water should be drawn up the tubing by osmosis forcing the liquid up the tube