J.R. S. answered 12/18/18
Ph.D. University Professor with 10+ years Tutoring Experience
Well, you forgot to put the units for hydrogen. You said it is 4.50 of hydrogen, but we don't know if that's 4.50 grams, or moles, or liters, or what. Here's the balanced equation. Maybe you can now answer the question, but if not, re-submit it and be sure to include the entire question, with all the units.
N2(g) + 3H2(g) ==> 2NH3(g)