Object: To demonstrate the phenomenon of dialysis with the help of a collodion bag. Requirements: Collodion bag, starch, salt, thread, beakers, water, iodine, silver nitrate, collodion (cellulose nitrate dissolved in ether and alcohol). Method: (a) Preparation of collodion bag: 1. Pour a small amount of collodion in a wide mouthed, clean and dry tube. 2. Revolve the tube so that [...]
Object: To demonstrate the phenomenon of diffusion. Requirements: Beaker, water, copper sulphate crystals. Method: Take a clean beaker and fill it completely with water. Place a big crystal of copper sulphate on one side of the beaker (Fig. 1). Observations: After some time, crystal of copper sulphate disappears and its particles get equally distributed throughout the water. Results: Molecules of [...]
If we keep hydrogen sulphide gas (H2S) exposed in any comer of the room, after a very short time the whole room is filled up with bad odour of the gas. In fact, this happens because the molecules of hydrogen sulphide gas gradually spread in the whole room. In other words, it can be said that the molecules of the [...]