Question

elemental phosphorus occurs as tetratomic molecules, p4. What mass in grams of chlorine gas is need to react completely with 455g of phosphorus to form phosphorus pentachloride?

Answer 1

P₄ + 10Cl₂ → 4PCl₅

mol P₄ = 455 : 123.895 g/mol = 3.672

mol Cl₂ = 10  x 3.672 = 36.72

mass Cl₂ = 36.72 x 71 g/mol = 2607.12 g