[Alexandra Jones]

Alexandra Jones  asked the Naked Scientists:

Dear Chris

As part of our year 8 science program my friend and I are planning to see if the different coloured fizzy drinks would effect the colouring of a white flower. I know people do the experiment with cut flowers and food colouring.

I thought we could water a white flowering plant with different coloured fizzy drinks. Now I am worried that the fizzy drinks may infact kill the plant .

I am also wondering, when you pour the fizzy drink that the soil will break down the chemicals of the fizzy drink and the  plant will only absorb the liquid and have no impact on the flower.
where can I find out about how flowers get their colour?

Any suggestions from you will help.

Thank you,
Alexandra

What do you think?

[RD]

I am also wondering, when you pour the fizzy drink that the soil will break down the chemicals of the fizzy drink and the  plant will only absorb the liquid and have no impact on the flower.

You could exclude the soil by growing the flowers hydroponically ...
http://en.wikipedia.org/wiki/Hydroponics

I'm not sure, but I don't think that a plant could be grown in undiluted fizzy drink because it is too acidic ~pH3,
and would kill the plant (as you suspected). The conditions for most plants should be only slightly acidic pH6(+/-0.5).
If the fizzy drink was diluted it would lower its acidity (pH) but would also reduce its colouring effect on the flower.


Food colouring or water-soluble ink may colour the flower without killing it if it is pH neutral.

Remember to water some flowers normally, with plain water, as a control to compare your artificially coloured flowers to.

[RD]

Here is a quick & simple experiment using coloured inks (or food colouring) and capillarity ...

http://library.thinkquest.org/19037/paper_chromatography.html