Question

A student prepared a solution of NaCl by dissolving 55.0g of sodium chloride in 570 mL of water. What is the percent by mass of the NaCl solution?

Answer 1

m(NaCl)=55.0 g
v=570 ml
ρ=0.9982 g/ml

m(H₂O)=vρ

w=m(NaCl)/[vρ+m(NaCl)]

w=55.0/[570*0.9982+55.0]=0.0881 (8.81%)