Science Buddies: "Ask an Expert"

Hi, I'm helping my daughter with her research for candy chromatography.
We found similar information on several sites.

http://www.weirdsciencekids.com/candych ... raphy.html
http://chemistry.about.com/od/chemistry ... chroma.htm (this one is the one referenced on science buddies)
http://www.scifun.org/homeexpts/candy.htm
https://www.sciencebuddies.org/science- ... p006.shtml

ALL of the sites say to make a 1% salt solution with 1/8 tsp of salt and 3 cups of water.
I have "done the math" over and over, and it seems to me that 1/8 tsp to 3 cups of water would make a 0.1% salt solution.

1/8 tsp salt = 0.71 g
3 cups of water = 709 ml
.71 / 709 = 0.001 = 0.1%

Am I right, or am I wrong?
It's embarrassing to me, as a scientist, that it seems that all of these sites copied each other without "doing the math" for themselves.
Or, maybe I'm the one who's got it all wrong.

Please help.
Thanks!

Hello and welcome to the forum!

I've looked at all your references, and done the math too, ... and it sure seems like 1g to 1000g is a 0.1% solution. I'll ask the other experts to weigh in on this...

Keith

Thanks! I will stay posted for more info from you.

1g/1L is clearly a 0.1% (one part in a thousand) by weight solution (and not a 1%: 1 part in a 100), so shame on the proof readers!

On the other hand, within limits, it really doesn't matter what the stock solution is provided it will disolve the the various test materials. All the measurements are relative. In this case, a 0.1% salt solution will hold more of the test materials than a 1% salt solution. The reality is that either a 0.1% or 1% solution would work for this experiment.

Thanks so much.

Before assuming an error, I might ask whether it was 1% by mass, 1% by volume, or 1% Moler. All three will give different concentrations. In any case, the salt concentration is almost irrelevant.