L.4 In research on the synthesis of superconductors, the reaction
Tl₂O3 (1) + 2 BaO(s) + 3 CaO (s) + 4 CuO (s) →
Tl₂Ba₂Ca3Cu4O12 (s) is being studied. (a) What amount (in moles)
of BaO is needed to react with 5.0 g of CaO? (b) Calculate the mass
of CuO required to produce 0.24 mol of product.