An aqueous solution of nacl has a mole fraction of 0.21. what is the mass of nacl dissolved in 100.0 ml of solution

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.