Ozone is made up of 3 atoms of Oxygen and present in stratosphere of our atmosphere. It prevents us from "Ultraviolet rays" of Sunlight so it is an important form of oxygen or us
Hope this helps!
A - 1 CH4+ 1 O2 = 1 CO2+2 H2
b - 2 Al+3 Cl2 = 2 AlCl3
c - 1 CH2O+ 1 H2 = 1 CH3OH
*The ones that have the coefficient of 1 you can leave blank but if you have to put a number just put 1
