Answer:
5 molecules of O2 reacted.
Explanation:
From the question, were told that 4 molecules of NH3 reacted with O2 to form 4 molecules of NO and 6 molecules of water. To know the molecules of O2 that reacted, we must generate a balanced equation. This is illustrated below:
4NH3 + O2 —> 4NO + 6H2O
From the above equation, we have a total of 10 atoms of O2 on the right side of the equation and a total of 2 atoms of O2 on the left side. To balance the equation, put 5 in front of O2 as shown below:
4NH3 + 5O2 —> 4NO + 6H2O
Now, the equation is balanced.
From the balanced equation, 5 molecules of O2 reacted.