How to convert g/L to mol/L

I know I should divide $\pu{g L-1}$ by the molar mass of the substance, but I don't seem to find the specific answer on Google. So just to be sure:


If I have $10^{-5}~\pu{g L-1}~\ce{Cu^2+}$ solution, do I have $1.57 \times 10^{-7}~\pu{mol L-1}$?


I think I'm missing something.




Yes. $$n = \frac{m}{M}~~~~~~~~~~n = cV$$
So $$c = \frac{m}{VM}$$


Given $\frac{m}{V}$ you can work out $c$ (in $\mathrm{mol~dm^{-3}}$).


 8

Grams of $\ce{Cu^{+2}}$ is ill defined. The $\ce{Cu^{+2}}$ did not get into the solution by itself. It was $\ce{CuCl2,CuSO4}$ or some other salt.


This is probably the reason for the discrepancy.


 0