Answer : The correct option is, (E) 6 moles.
Explanation : Given,
Moles of nitrogen = 2 moles
The given balanced chemical reaction is:
[tex]N_2+3H_2\rightarrow 2NH_3[/tex]
From the balanced chemical reaction we conclude that,
As, 1 mole of nitrogen gas react with 3 moles of hydrogen gas
So, 2 mole of nitrogen gas react with [tex]2\times 3=6[/tex] moles of hydrogen gas
Therefore, the number of moles of hydrogen gas needed to react with 2 moles of nitrogen gas is, 6 moles.