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Author Topic: why do potatoes in salt water absorb food colouring?  (Read 4523 times)

paul.fr

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We had two containers with a few pieces of potato in then, one container had tap water, the other salt water. When food colouring was added, the potato in the salt water absorbed the colouring and the tap water did not! Why is that? Should the salt water soaked potato be doing some sort of osmosis and so not absorb the colouring?


 

lindsayle19

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why do potatoes in salt water absorb food colouring?
« Reply #1 on: 30/04/2009 08:08:39 »
I don't know. I have no idea there.

Why don't you try to search on Google or try to ask it to your friends.?
 

Offline 112inky

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why do potatoes in salt water absorb food colouring?
« Reply #2 on: 30/04/2009 19:39:39 »
due to osmasis
 

Offline Karsten

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why do potatoes in salt water absorb food colouring?
« Reply #3 on: 01/05/2009 20:59:00 »
Maybe the salt water did something to the surface of the potato?

It seems that the water in the potato should try to balance by flowing toward the saltwater. Unless the potato is saltier than the water.
 

Offline Bored chemist

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why do potatoes in salt water absorb food colouring?
« Reply #4 on: 02/05/2009 17:22:44 »
due to osmasis
The original post mentioned osmosis and got the spelling right.
However the usual way that osmosis would happen would be thatwater would leave teh potato to try to get the osmotic pressure the same in the plant cells as in the solution round them so that odesn't seem to help explain the effect.
One possibillity is salting out.
Another is that the salt kills the cells of the spud and the dead tissue not longer has an intact cell membrane so the dye soaks in.
 

The Naked Scientists Forum

why do potatoes in salt water absorb food colouring?
« Reply #4 on: 02/05/2009 17:22:44 »

 

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