J.R. S. answered 03/26/20
Ph.D. University Professor with 10+ years Tutoring Experience
Al2O3 + 6HCl ==> 2AlCl3 + 3H2O ... balanced equation
moles Al2O3 present = 25.0 g x 1 mol/101.96 g = 0.245 moles
moles AlCl3 produced (assuming HCl not limiting) = 0.245 mol Al2O3 x 2 mol AlCl3/mol Al2O3 = 0.490 moles
mass AlCl3 produced = 0.490 moles AlCl3 x 133 g/mol = 65.2 g AlCl3 produced