__NH3(g) + __ O2(g) → __ N2(g) + __ H2O(g)

Question

When the reaction above is completely balanced, the coefficient for NH3 will be

(a)
2.
(b)
3.
(c)
4.
(d)
6.

Answer 1

I get
4 NH3 + 3 O2--> 2 N2 + 6 H2O