Answer:
14.336 g MnFâ
Explanation:
number of moles = mass / molecular weight
number of moles of MnIâ = 55 / 309 = 0.178 moles
number of moles of Fâ = 55 / 38 = 1.447 moles
From the reaction and the number of moles calculated we deduce that the fluorine Fâ is a limiting reactant.
So:
if     13 moles of Fâ reacts to produce 2 moles of MnFâ
then  1.447 moles of Fâ reacts to produce X moles of MnFâ
X = (1.447 Ă 2) / 13 = 0.223 moles of MnFâ (100% yield)
For 57.2% yield we have:
number of moles of MnFâ = (57.2 / 100) Ă 0.223 = 0.128 moles
mass = number of moles Ă molecular weight
mass of MnFâ = 0.128 Ă 112 = 14.336 g