In one process of 5.75 kg of CaF2 are treated with an excess of H2SO4 and yield 2.85 kg of Hf calculate the percent yield of hf?

Answer 1

Do you mean HF as in hydrofluoric acid. Hf is hafnium.
Write and balance the equation.
Convert g CaF2 to mols. moles = grams/molar mass.

Use the coefficients to convert mols CaF2 to mols HF (not Hf)

Convert mols HF to g. g = mols x molar mass. This is the theoretical yield (T. E.).

%yield = (actual yield/T.E.)*100 = ?

Answer 2

86.55%