You have a solution that contains 12.0 g of NaCl in 50.0 g of water. Calculate the NaCl concentration in units of...
mass percent and mole fraction
would the mole fraction be
12/12+50=.1935
no.
What you have calculated as mole fraction actually is mass fraction. Multiply that by 100 to get 19.35% for mass percent.
mole fraction is mols NaCl/total mols.
mols NaCl = 12/molar mass NaCl = ?
mols H2O = 50/molar mass H2O = ?