Topic 1 - Diffusion and Osmosis Practicals

Question 1

how do you investigate diffusion in a non-living system?

Answer 1

make some agar jelly with phenolphthalein and dilute sodium hydroxide, and put it into a beaker of dilute hydrochloric acid. eventually, the cubes will become colourless as the acid diffuses into the jelly and neutralises the sodium hydroxide

Question 2

how do you investigate osmosis in a living system?

Answer 2

put identical cylinders in two beakers with a concentrated sugar solution and pure water. leave the potatoes for half an hour, take them out and measure their lengths.

Question 3

how do you investigate osmosis in a non-living system?

Answer 3

put some visking tubing at the end of a thistle funnel. pour some sugar down the funnel and put it into a beaker of pure water and measure where the sugar solution comes up to. leave overnight and the solution should be forced up the tube as water is drawn in.