Finding Mass of Solute


by Sayuri09
Tags: density, mass, solute, solution, volume
Sayuri09
Sayuri09 is offline
#1
Nov4-09, 12:58 AM
P: 5
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!!!
Phys.Org News Partner Science news on Phys.org
Better thermal-imaging lens from waste sulfur
Hackathon team's GoogolPlex gives Siri extra powers
Bright points in Sun's atmosphere mark patterns deep in its interior
Borek
Borek is offline
#2
Nov4-09, 02:32 AM
Admin
Borek's Avatar
P: 22,669
Basically you can't do anything without knowing more. You can use density tables to check out concentration.

--
methods


Register to reply

Related Discussions
How can water have a molarity if theres no diff b/w solute and solvent? Biology, Chemistry & Other Homework 8
finding the mass of an atom - bainbridge mass spectrometer question Advanced Physics Homework 1
Fraction of solute in two layers Biology, Chemistry & Other Homework 4
Determining which Nonpolar Solute most likely to be soluble in nonpolar solvent Biology, Chemistry & Other Homework 1
Molar Mass of Unknown Solute and Mole Fraction of Gases Biology, Chemistry & Other Homework 7