posted by Sarah on .
I have a question here and I know what the answer is supposed to be, and I also know that I know how to do it but I can't for the life of me remember how...any help would be apprecaited. Thanks alot.
You are supplied with a soultion of mordant yellow that has a concentration of 3.3 x 10-5 M and a molecular weight of 358.3g/mol. In a 10ml volumetric flask, put 0.05g of alpha-cyclodextrin which has a molecular weight of 972.9g/mol and then fill to the mark with the mordant yellow solution. This gives a cyclodextrin/mordant yellow stock solution. What is the concentration of the cyclodextrin in the soultion, where the concentration of mordant yellow is still 3.3 x 10-5M?
Let's call alpha-cyclodextrin acdl.
mols acdl = 0.05 g/molar mass acdl.
mols acdl/0.010 L = concn in mols/L = M.
I may have missed something so check my thinking.
I was thinking the exact same thing after I posted that today... I think I was thinking it was more complicated because it had so much information, but also cause I think I read it as the total concentration, not the concentration of one. Anyways, thanks alot for your help!