An aqueous solution contains 32.7% KCl (wt/wt%). what is the mole fraction of KCl in the solution

The mole fraction of KCl in the solution is 0.1051

calculation

mole fraction of KCl in solution = moles of KCl / total number of moles (moles of KCl + moles of H2O)

moles=mass/molar mass

mass of KCl=32.7g

molar mass of KCl = 39 + 35.5

moles of KCl is therefore = 32.7g/74.5 g/mol=0.439 moles

find the moles of H2O = mass of H2O/molar mass

mass of H2O=100-32.7=67.3g

molar mass of H2O = (1 x2) + 16=18 g/mol

moles = 67.3/18 = 3.739 moles

total moles=3.739+0.439=4.178 moles

mole fraction is therefore=0.439/4.178=0.1051