Question

A 33.6% w/w NaCl(aq) solution has a density of 1.0492 g/mL. Convert weight percent to molarity.

Answer 1

% (W/W) =

given , % (W/W) of NaCl (solute) = 33.6

hence, 33.6 g NaCl is dissolved in 100 g solution

moles of solute ( NaCl) = (mass / molar mass) = (33.6 58.5) = 0.574  

density of the solution = 1.0492 g/mL

then volume of the solution = (mass of solution./density )

=   

= 95.31 mL

= 95.31 mL

= 0.0953 L

now , molarity =  

so, molarity of NaCl solution =   = 6.023 mol/L.