4Cа + O2 -----> 2 Cа2O Use the chemicаl equatiоn abоve tо calculate moles of Ca2O that would react with 4.0 mol O2. You only need to put in the answer - I do not need to see your calculations that you did to get the answer. Also be sure to add the units to your answer - which on this problem will be just mol.