When the following equation is balanced with lowest whole-number coefficients, what is the coefficient for NO(g)? ___NH3(g) + ___O2(g) → ___NO(g) + ___H2O(g)

Coefficient in front of the in the balanced equation - 4

Explanation:

The unbalanced reaction is shown below as:-

On the left hand side,  

There are 1 nitrogen atom and 3 hydrogen atoms and 3 oxygen atoms

On the right hand side,  

There are 1 nitrogen atom and 2 hydrogen atoms and 2 oxygen atoms

Thus,  

Right side, must be multiplied by 6 and by 4

Left side, is multiplied by 5 and by 4 so to balance the whole reaction.

Thus, the balanced reaction is:-

Coefficient in front of the in the balanced equation - 4