Question

What mass of PCl3 forms in the reaction of 70.6 g P4 with 268 g Cl2 ?

P4 + 6Cl2 → 4PCl3

Answer 1

hom many moles of P4 do you have.
how many moles of CL2 do you have.
figure those.

Now, if you have less than six Cl2 moles for the moles of P4, then CL2 is the limiting reagent. The product will equal 4/6 of the moles of CL2 you have.

If you have more than six moles of Cl2 for the moles of P4, then P4 is the limiting reagent, and you will get four times the P4 moles , as the product PCl3