1200 g of crude zirconium containing 95.0% Zr (rest oxide and nitride impurities that do not react with iodine) is heated with iodine in the van Arkel process, $Zr + 2 I X_{2} ZrI X_{4}$ . With Zr = 91 and I = 127, the mass of $I X_{2}$ that combines with the zirconium in one complete conversion is

Answer: D

n(Zr) = 0.950 x 1200/91 = 12.527 mol. Each Zr needs 2 mol of

I X_{2}

(M = 254 g/mol), so n(

I X_{2}

) = 25.055 mol. Mass = 25.055 x 254 = 6364 g. In practice the iodine is regenerated at the filament and recycled.