Chapter 4 - Sections 4.1-4.9 - Exercises - Cumulative Problems - Page 190: 100

7.51%

Mass of solute= Number of moles of solute$\times$Molar mass =Molarity$\times$Volume$\times$Molar mass Mass of the solution=Density$\times$Volume Mass percent=$\frac{Mass\,of\,solute\times100}{Mass\,of\,solution}$% $=\frac{Molarity\times Molar\,mass\times100}{Density\,of\,the\,solution}$% $=\frac{1.35\frac{mol}{L}\times58.44\frac{g}{mol}\times100}{\frac{1.05g}{10^{-3}L}}$%= 7.51%