| | Re: Unit conversion
Grams (like in ng) are an absolute measure, at least in earth at 1 atm and 1 grav; while molarity (like in uM) is relative: talking about mass a gram of NaCl is equal to a gram of EDTA, but a 1 M NaCl is not equal to 1 M EDTA.
Molarity is a measure of concentration that depends on molecular weight (MW) of the substance, and the final volume of the solution your preparing. Let's take NaCl as example: its MW=58.44 , dissolve 58.44 g in 1 L of ddH2O and you will have a 1 M NaCl solution. Further dilutions can be made from there (in paper, you don't have to prepare that much solution if not needed): 1 M = 58.44 g in 1 L or 5.844 g in 100 ml or 0.5844 g in 10 ml, etc.
What you need to do is to investigate the MW of the reagent (or whatever it is) and use some math. This formula can give you hint:
C1V1 = C2V2
If you want further help or to directly solve your question at least mention the reagent you are working with and the volume you need.
Last edited by luisillo; 05-23-2013 at 02:11 PM.