(A) A 1.00 g sample of a magnesium-aluminum alloy yields 0.107 g H₂ when treated with an excess of HCl(aq). What is the percentage by mass of Al in the alloy?

(B) A 1.500 g sample of a mixture containing only Cu₂O and CuO was treated with hydrogen to produce copper metal and water. After the water evaporated, 1.2244 g of pure copper metal was recovered. What is the percentage by mass of Cu₂O in the original mixture? Balanced chemical equations are given below for the reactions involved.

CuO(s) + H₂(g) → Cu(s) + H₂O(l)
Cu₂O(s) + H₂(g) → 2 Cu(s) + H₂O(l)