What is the mass percent of sodium chloride in a solution in which 50 grams of NaCl is dissolved in 700 grams of water?

Moles of NaOH = 15.0 g NaOH *

1

mol NaOH

40.00

g NaOH

= 0.375 mol NaOH

Calculate the number of litres of solution present.

Volume = 225 mL *

1

L

1000

mL

= 0.225 L soln

Divide the number of moles of solute by the number of litres of solution.

Molarity =

0.375

mol

0.225

L

= 1.67 mol/L