N2 + 3 H2 --> 2 NH3 The balanced equation above indicates that if 2 moles of N2 react, then

2 moles of H2 will also react
3 moles of H2 will also react
4 moles of NH3 will be produced
2 moles of NH3 will be produced

4 moles of NH3 will be produced

Explanation:

The reaction expression is given as:

            N₂  +  3H₂  →  2NH₃

We have to check that the equation of the reaction is balanced.

 Then;

      if 2 mole of N₂ reacts;

 1 mole of N₂ will react with 3 mole of H₂ to produce 2 mole of NH₃

2 mole of N₂ will react with (2x3)mole of H₂ to produce (2x2)mole of NH₃

                                                    6mole of H₂ to produce      4 mole of NH₃