According to the equation given, we have N2 + 3H2 → 2NH3.
Therefore, to determine the moles of NH3 we have to do the following-
1.3 mol H2 × 2 mol NH3 / 3 mol H2 = 0.87 mol
Answer: .87 moles of NH3 are produced from 1.3 moles of H2.
I hope this helps!