Which is the next logical step in balancing the given equation?
n2 + o2 → no2
place the coefficient 2 in front of oxygen and nitrogen dioxide.
place the coefficient 3 in front of oxygen and nitrogen dioxide.
the equation is already balanced.
change the subscript of the nitrogen molecule to 1.

To balance the give n equation, we apply elemtal balance and count each elements per side. There are 2 nitrogens in the left side so there should be 2 moles of NO2. Since there are already 4 moles of O in the right side, there should be 2 moles of O2. Hence answer is a. Place the coefficient 2 in front of oxygen and nitrogen dioxide.