Answer:
109.2g
Explanation:
First, let us obtain the number of mole of lithium fluoride in the solution. This is illustrated below:
Molarity of lithium fluoride (LiF) = 3.5M
Volume = 1.2L
Number of mole of LiF =?
Molarity = mole/Volume
Mole = Molarity x Volume
Number of mole LiF = 3.5 x 1.2
Number of mole LiF = 4.2 moles
Now let us convert 4.2 moles to grams in order to obtain the desired result. This illustrated below:
Molar Mass of LiF = 7 + 19 = 26g/mol
Number of mole of LiF = 4.2 moles
Mass of LiF =?
Mass = number of mole x molar Mass
Mass of LiF = 4.2 x 26
Mass of LiF = 109.2g
Therefore, 109.2g of lithium fluoride is required.