Osmosis Coursework (GCSE)

We did an experiment on osmosis - putting potato pieces into test tubes containing different concentrations of sucrose solution; leaving it; weighing the before & after mass; then working out percentage mass change. The graph of conc vs % mass change shows a sigmoid curve. I've nearly finished, but for the Evaluate section I have to come up with an alternative method to investigate the same variable. What else could I do apart from what I did? Thanks!

Reply 1

rosy123

i did this experiment last year and got an A* by adding ways in which you could extend the experiment you had already done, rather than do a totally new one, and investigating other factors. any help?

Reply 2

corkskrew

Depends what it was you were actually investigating.
Even so, all my E6a and E6b marks (I remember this well... just helped my brother with his GCSE cwk) were for what went wrong, what could have been done better, things you would change if you conducted the same investigation again. So you could suggest keeping the temp constant by using a water bath or something. Or using a pH buffer. Or find a more accurate way to choose the potato samples used (keeping surface area constant is more valuable than the mass being constant)

Reply 3

Excalibur

Sorry, I was investigating concentration (of the sucrose), against how much osmosis takes place, by weighing the potato. At a high conc the potato lost mass and at a lower one it gained mass.

How could you keep the surface area constant?