1. The problem statement, all variables and given/known data I'm doing an experiment for Science Fair, and one of the parts requires that I know the mass of a solute (NaCl) dissolved in a solvent (water). Is there any equation I can use to find this? I cannot use concentration, but I have the total mass of the solution, the total volume of the solution, and the molar mass of the solute (NaCl). I can also calculate the total density of the solution, so let's add that, as well. 2. Relevant equations For the solute: Mass = Molarity x Molar Mass x Volume 3. The attempt at a solution Using the equation above, I've tried to plug in different variables in the place of variables I didn't know up-front. Mass = Molarity x Molar Mass x Volume Mass = (Moles / Volume) x Molar Mass x Volume Mass = ((Mass / Molar Mass) / Volume) x Molar Mass x Volume Mass = ((Mass / Molar Mass) / (Mass / Density)) x Molar Mass x (Mass / Density) Of course, simplifying all of this cancels Mass, what I was trying to find in the first place, which makes me wonder why I even did all of that substitution for nothing. I'm thinking there's a different, better way to do this, probably a different equation. But, also, because I am doing this within an experiment, any hands-on method would work, too (just something feasible, please?). Thanks in advance!!!
Basically you can't do anything without knowing more. You can use density tables to check out concentration. -- methods