Answer:
Explanation:
Solution required is .15 M 500 mL sodium fluoride .
molecular weight of sodium fluoride = 42
one mole of sodium fluoride = 42 grams
No of moles contained in the solution of .15M , 500 mL solution
= .15 x 0.5 moles = .075 moles
1 mole = 42 g
.075 moles = .075 x 42 = 3.15 grams .
So mass of sodium fluoride required = 3.15 g .