B19

But then this will be discussion and I don't want any discussion, but answer.

Hey, I am very confused with calculations and I guess I am mixing molecular mass with molar concentration. I just want straight answer for two questions about how to make calculations: 1. I have a liquid with molecular weight = 40 and I want to prepare 15ml of 100mM stock. It is not a powder like for example NaCl. 2. I have 50ug of lyophylized chemical and molecular weight = 500 and I want to use it all (50ug) to prepare 500mM of stock. Thanks a lot. B19