Respuesta :

Answer is: mass of lithium fluoride is 3,732 grams.
m(solution) = 18,66 g.
ω(solution) = 20% = 20% ÷ 100% = 0,2.
m(LiF) = ?
ω(solution) = m(LiF) ÷ m(solution).
m(LiF) = ω(solution) · m(solution).
m(LiF) = 0,2 · 18,66 g.
m(LiF) = 3,732 g.