Chemistry Help, exam tomorrow!!

Question

how many grams of phosphorus chloride are produced from 93g of P4(s) and 213g of Cl2(g) assuming the reaction goes to completion? The balanced equation for the reaction is P4(s) + 6Cl2(g) ---- 4PCl3(g)

Answer 1

P₄ + 6Cl₂ ==> 4PCl₃

Moles P₄ present = 93 g x 1 mol/123.9 g = 0.751 moles

Moles Cl₂ present = 213 g x 1 mol/70.9 g = 3.00 moles

Limiting reactant is Cl₂ because it requires 6 mol Cl₂ per 1 mol P₄

Theoretical yield of PCl₃ = 3.00 mol Cl₂ x 4 mol PCl₃/6 mol Cl₂ x 137 g/mol PCl₃ = 274 g of PCl₃

Answer 2

P4(s) + 6Cl2(g) ---- 4PCl3(g)

93g P4 x (1 mol P4/123.90 g P4) x (4 mole PCl3/1 mol P4) = 3 mol PCl3

213g Cl2 x (1 mol Cl2/70.90 g Cl2) x (4 mole PCl3/6 mol P4) = 2 mol PCl3

So, Cl2 is the limiting reactant.

2 mol PCl3 x (137.33 g PCl3/1 mol PCl3) = 274.66 g PCl3