Chemistry help for the calculating percent yield.?

Question

6.00kg of CaF2 treated with excess H2SO4 and yield 2.86 kg of HF. What is the percent yield of HF?

Answer 1

Hydrogen fluoride contains the fluorine from CaF₂.  So to find the yield of the reaction with respect to HF is the ratio of fluorine in HF to that in CaF₂.

Divide the mass of the fluorine atoms by the total mass of a CaF₂.molecule, and you get the mass fraction of fluorine

w₁ = 2∙19 amu / 78.08 amu = 48.67%

the mass of fluorine in the reactant is:

m₁ = 0.4867 ∙ 6kg = 2.92kg



Same procedure for product:

w₂ = 19 amu / 20 amu = 95.0%

the mass of flourine in the product is:

m₂ = 0.95 ∙ 2.86kg = 2.717kg

Hnece the yield of HF is:

Y = 2.171kg / 2.920kg = 93%