Question

The mole fraction of NaCl in an
aqueous solution is 0.132. What is
the weight/weight percent of NaCl in
this solution?
Molar Mass
NaCl: 58.44 g/mol
H20: 18.016 g/mol
Hint: Remember to give your answer as a percent!

Answer 1

The weight/weight percent(%w/w) of NaCl in  solution : 33.03%

Further explanation

Given

Mole fraction of NaCl : 0.132

Required

The weight/weight percent of NaCl

Solution

1 mol solution : 0.132 mol NaCl + 0.868 mol H₂O

mass NaCl :

$\tt 0.132\times 58.44 g/mol=7.714~g$

mass H₂O :

$\tt 0.868\times 18.016~g/mol=15.64~g$

Total mass = 7.714 + 15.64 = 23.354 g

$\tt \%NaCl=\dfrac{7.714}{23.354}\times 100\%=33.03\%$