Answer : The number of moles of oxygen gas required are 13.7 moles.
Explanation : Given,
Moles of
= 27.4 moles
The given balance chemical reaction is:

From the balanced chemical reaction we conclude that,
As, 2 moles of
react with 1 mole of

So, 27.4 moles of
react with
mole of

Therefore, the number of moles of oxygen gas required are 13.7 moles.