We have an aqueous solution that contains

47% (by mass) of a hypothetical solute Z. The
formula weight of the solute Z is 209 g/mol.
The density of the solution is observed to be
1.3 g/mL. What is the molarity of Z in this
solution?
Answer in units of mol/L

2 answers

1.3 g/mL x 1000 = ? g = mass of 1L soln.
?g x 0.47 = ? g Z in the L.
mols Z = ?g Z/209 = ? mols in that L; therefore that is the M in moles/L.
Thank you for your help.