please help me to do coursework using salt solution and a potatoe HELP!!

hey im doing as level biology and for my coursework im doing the water potential of a potatoe using salt solution. My plan is to weigh tubes of potatoe flesh from the same potatoe and then place them in salt solutions (pure water, 0.2, 0.4, 0.6, 0.8, and 1M)for 24 hours and then reweigh them. I think that i will get a rise in mass up to 0.4 then a decrease in mass above that.The problem is that then i get stuck and i dont know how to find the water potential of the potatoe using the results. do i need to no the solute potential of the salt solution?, or do i already no them(0.2 etc) really i kinda have no clue about the rest of it. If anyone has ever done this coursework or just has any info that would help me in this coursework it would be great and id be soooo greatful!
Thanks
Zoe :hello:

Reply 1

samsonmoley

IS THERE ANYBODY OUT THERE?????????????? (think in welsh accent :sheep:

aka titanic :captain:

and ewan thing a me bob just to help you get the picture here)

Reply 2

dinesh

You need to plot your results on a graph of COncentration VS change in length. intrapolate to get change in length=0 and that is the potential of the potato, the point at which there is no net movement of water.
This is quite a common AS lab, came for November 2004 also.