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Osmosis and the density of solution

Today we did an experiment in which we had various concentrations of a solution, I think it was sucrose.
We then added potatoes to these solutions and left them for 15 minutes. AFfer this, we added dye to each solution and added a drop of each solution to another solution of equal concentration for each.

The dyed drop would sink in some test tubes and float in others, but our teacher didn't really explain it well, so i have no idea why. It's something to do with osmosis. Could anyone explain?:/

Reply 1

aersh8

If the potatoes contained little water (ie were placed in a concentrated solution initially so the water moved in by osmosis) the dye would drop since water would move into the potatoes.

The opposite would happen if the potato contained a lot of water (ie was placed in a dilute solution) as water would move out and push the dye up.