Question

27 g of Al will react with how much mass of O2 to produce Al2O3

Answer 1

Given Grams of Al-->Molar Mass of Al-->Moles of Al-->Mole to mole ratio to get moles of Al2O3--->Molar Mass of Al2O3--> grams of Al203

Answer 2

4Al + 3O2 ------> 2Al2O3

no. of moles of Al = 27g/ 27gmol^-1
= 1mol

No. of moles of O2--------. 3/4 mol
mass of O2 in that amount of moles = 3/4 x 32
= 24g