Question

What is the limiting and excess reactants in the reaction between 3 moles of NH3 and 6 moles of CuO?

Answer 1

3CuO + 2NH₃ → 3Cu + N₂ + 3H₂O

According to the reaction equation for one mole of NH₃ we need $\frac{3}{2}= 1.5$ moles of CuO.

Proportion: 1: 1.5

In this problem there are 3 moles of NH₃ and 6 moles of CuO

Proportion: 3: 6 = 1 :2

So, NH3 is limiting reactatnt and CuO is excess reactant.