# concentration question - (Mar/12/2007 )

How to calculate concentration from formula weight and density.

-samita-

QUOTE (samita @ Mar 12 2007, 02:03 AM)

How to calculate concentration from formula weight and density.

It is impossible because as so each substance with equal mol weigt will have the same concentration and what's about density which is unique property for any compound????

I think it is not enough, you need mol number in your define solution volume to transform Mw to gram

Then %= (mol*Mw)/(density*Volume)*100

-circlepoint-

I mean I have chemicals in solution form from supplier. Its molecular weight i hope F.G=99.16 and density =1.013 is given i want to know its concentation from these two values.

-samita-

is it a solution or a liquid chemical?

-mdfenko-

Its a liquid chemical

-samita-

QUOTE (samita @ Mar 13 2007, 12:40 PM)

Its a liquid chemical

okay.

the density is 1.013 which means that it is 1.013g/ml or 1013g/liter. with a formula weight of 99.16 g/mole the concentration is 1013/99.16 = 10.216 moles/liter (assuming 100% purity).

-mdfenko-

QUOTE (samita @ Mar 12 2007, 02:03 AM)

How to calculate concentration from formula weight and density.

If you want to learn the molarity of the original bottle of the compound, you can use this formula:

Molarity of the original bottle (M)= (% of the compound X d (g/mL) X 1000) / molecular weight (g/mol)

-real science-