If the mass of sodium chloride, NaCl (MW = 58.5 g/mol), is 40.0 g and the mass of water is 30.0 g, what is the mole fraction of NaCl in the solution?

a. 0.291

b. 0.60

c. 0.40

d. 40.0

e. 0.240

What is the mass percent of NaCl in the solution in the previous question?

a. 0.291

b. 0.60

c. 0.40

d. 40.0

e. 0.240