How many moles of PI3 form when 0.305 moles of P and 0.521 moles of I2 react according to, 2P+3I2=2PI3

Question

 Having trouble understanding if this has to do with theoretical yield.

Answer 1

It has to do with the concept of limiting reagent.  Which of those two reactants will be totally consumed first?  Do a quick dimensional analysis - paying particular attention to the stoichiometry of the balanced equation and the mole ratios of the reactants.  The solution is straightforward from there.