Whats the mass of Aluminium Oxide when 135g of Aluminium is burned in Air? Show workings

-First balance out the Equation [4Al + 3O² = 2Al²O³] -Find the Relative Formula mass of the Reactants and Products you want [Al=27. O²=32] [Al²O³ = 102] -Find the number of moles in the Substances you already know [Aluminium in this case] [135 divided by 27 = 5 moles] -Using that, use the Balanced equation to how many moles in Aluminium Oxide [If there is 5 Moles in Aluminium, and there is 4 lots of it, the ratio will be 1:1.25. Since Aluminium Oxide has 2 lots, it will have 2.5 Moles involved ] -Finally get the mass of Aluminium Oxide [2.5 x 102 = 255 grams]