Question

A solution of the solute hexane and the solvent acetone that is 28.1 g hexane per 100. g solution is available. Calculate the mass (g) of the solution that must be taken to obtain 0.646 kg of CH3(CH2)4CH3.

Molar Mass (g/mol)
CH3(CH2)4CH3 100.21
(CH3)2CO 58.05

Density (g/mL):
CH3(CH2)4CH3 0.6838
(CH3)2CO 0.7899

Name/Formula:
hexane
CH3(CH2)4CH3
acetone
(CH3)2CO

Answer 1

You have a solution that is 28.1 g solute/100 g solution. You want 646 g of the solute. Wouldn't that just be
646 x (100/28/1) = ?? OR

by ratio/proportion
(28.1/100) = (646/x)
x = 646 x 100/28.1 = ??
You can check it to make sure it is ok. If I do the math I get close to 2299 g solution needed.
So 646g solute/2299 g soln = 0.281/g or 28.1/100g
Check my thinking. Check my work.