Answer:- 46.4 g of NaCl is dissolved.
Solution:- Mole fraction of NaCl = 0.21
Since we have an aqueous solution of NaCl, it means NaCl is dissolved in water.
sum of mole fractions is always 1.
So, mole fraction of water = 1 - mole fraction of NaCl
mole fraction of water = 1 - 0.21 = 0.79
If we have total 1 mol of the solution then there are 0.21 moles of NaCl and 0.79 moles of water.
mass of NaCl = 0.21 x 58.44 = 12.3 g
mass of water = 0.79 x 18.0 = 14.2 g
If we assume the density for the solution is 1g/mL then 100.0 mL solution is 100 g solution.
From mass of NaCl and water, the mass of solution = 12.3 + 14.2 = 26.5g
From here, 26.5 g of solution has 12.3 g of NaCl. 100 g of solution has how many grams of NaCl?
We could use the proportions here..
12.3/26.5 = X/100
12.3(100) = 26.5(X)
X = 1230/26.5
X = 46.4
So, 46.4 g of NaCl is dissolved in 100.0 mL of solution.