What is the mass of a #"7% HCl"# solution in which #"45.0 HCl"# has been dissolved?
The mass of the solution is
In this case, where the mass of the solute is known, and the mass of the solution is desired, the basic equation for percent concentration is the mass of solute divided by the mass of the solution multiplied times 100%.
mass of solute =
percent concentration =
mass of solution
Solution: Rearrange the equation for percent concentration to isolate mass of solution. Plug in the known values and solve.