Hello everyone,
Chemistry graduates?
I need some help over here. Any suggestions on calculating the molarity of acids (any acids especially the strong ones) as no information are given on the bottle except for the MW and the percentage of purity?
I don't know whether this is an appropriate site to ask such a Q or any suggestion of good forum sites?
Thanks very much.

Telephone the manufacturer and ask for the technical helpline. They may be able to tell you the molarity but if not, they should be able to tell you the density i.e. mass per volume (usually expressed as g/mL). From this, you can work out the molarity in the usual way (no. of moles = mass/molar mass) adjusting it accordingly if not 100% pure, see here:

http://www.physicsforums.com/archive/index.php/t-84435.html

Thanks Ann,
But just wondering, will it be that precise if we measure out the weight of the acid ourselves? e.g. for 1 mL what is the weight of the solution (on an analytical balance)...

I'd rather find out the density from the manufacturer than try to determine it using an analytical balance - I guess it depends on how accurate you need to be but once you take into account the error in the pipette measurement of 1mL (which could be considerable if your conc. acid is viscous) and the error in the balance read-out, your measured density could be out by a quite a lot. Ring (or e-mail) the technical helpline, that's what they are there for and they're usually very helpful. Alternatively, you could look up a literature density value (Merck Index?) but given the choice, I'd still phone the helpline as they will have the details for your specific product. Good luck

Thanks Ann, really appreciate that

You're welcome

Hi Ann,
Just asking, what field are you currently in? Chemistry? Doing PhD? At which uni? If you don't mind to share...