[angel68]

density of 1.24g/mL and is 9.14M. Calculate the % by mass in solution. (MW is 63.02g/mL)?

mass solute
------------- x 100 = mass percent
mass solution

(1.24g/mL)(1000mL) = 1.24 x 10^3g --> mass solution

M=mole solute
   ------------
    L solution
I'm having trouble with next step.... Do I use the 9.14M to help get the mass of solute or do I use the MW?

Thanks for your help

[Borek]

http://www.chembuddy.com/?left=concentration&right=percentage-to-molarity

You will just have to do the reverse.

[angel68]

http://www.chembuddy.com/?left=concentration&right=percentage-to-molarity

You will just have to do the reverse.

I'm sorry the reverse of M??? 

[Borek]

No, you have to use the same approach to find out formula for molarity to percentage conversion.

Or - to make things much faster - don't derive everything, just solve final formula for percent concentration.

[angel68]

No, you have to use the same approach to find out formula for molarity to percentage conversion.

Or - to make things much faster - don't derive everything, just solve final formula for percent concentration.

Thanks so much!!! I appreciate your help.