How many grams of a 23.4% by mass NaF solution is needed if you want to have 1.33 moles of NaF?

Question

a)55.9
b)13.1
c)31.1
d)239
e) none of the above

Answer 1

R.M.M of NaF = 41g

1.33 mols of NaF = 54.53g

In 100g solution, there is 23.4 g NaF. So, if you need 54.53g

NaF, the volume of the solution you need is, 133g

So the answer is e.

Answer 2

molar mass of NaF=23+19=42

1.33 moles=1.33*42=55.86g

so 55.86/0.234=238.7g are needed