Science Buddies: "Ask an Expert"

My daughter is trying to do the science project as described under
https://www.sciencebuddies.org/science- ... #materials

After following the method described, we are not able to see the carbon granules absorbing any die color, it remains
the same after experiment, Also when carbon powder is used the color turns black, we are following what is described in the science project, not sure what we are doing is wrong, any help is appreciated.

Hi there,

It is possible that the carbon granules do not have as high of a surface area to volume ratio so the same amount isn't as effective as the powder--so your results may be valid. I would re-try the experiment and see if you see any change of the color intensity after filtering under this condition.

Do you mean that after filtration your solution remains black? It sounds like your filter isn't removing the charcoal particles from the solution. You could try using more layers of coffee filters, or what is commonly done is to make a wet pad of either sand or diatomaceous earth (this is probably more effective- also is sold at some pet stores, grocery stores, Amazon.com, etc.). I would put some of the diatomaceous earth in the coffee filter, wet it with water, and then pour your solution through. This is a very fine powder and should be small enough to "catch" any charcoal particles from falling through your filter-- I use this technique often in lab and it works great!

Let me know if you have any more questions!

Erin