Question

Pentacarbonyliron(0) (fe(co)5) reacts with phosphorous trifluoride (pf3) and hydrogen, releasing carbon monoxide: fe(co)5+2pf3+h2→fe(co)2(pf3)2(h)2+3co if 6.0 g of fe(co)5 reacts with 4.0 g of pf3 and 4.0 g of h2, which is the limiting reagent?

Answer 1

The limiting reactant can be determined by calculating the moles supplied / moles stoich ratio and the lowest is the limiting reactant.

Fe(CO)5 ratio = [6 g / 195.9 g/mol] / 1

Fe(CO)5 ratio = 0.0306

 

PF3 ratio = [4 g / 87.97 g/mol] / 2

PF3 ratio = 0.0227

 

H2 ratio = [4 g / 2 g/mol] / 1

H2 ratio = 2

 

We can see that PF3 has the lowest ratio, so it is the limiting reactant.