mole ratio is equal to 4 moles to give 5 mole of oxygen and 2 moles of the product . writing the mole ratio of a reaction does not require or is not a special procedure , just write the stoichiometric coefficients of all reacting substances .So in this case just say 4 is to 5 is to 2. Sorry i cant find my ratio sign so take the (is to) as aratio symbol
