J.R. S. answered 02/13/20
Ph.D. University Professor with 10+ years Tutoring Experience
2 HCl(aq) + 1 Ba(s) → 1 BaCl2(aq) + 1 H2(g) ΔH°rx = -538.88 kJ
mol Ba present = 71.41 g x 1 mol/137 g = 0.521 mol
mol HCl present = 0.290 L x 0.616 mol/L = 0.179 mol
Limiting reactant is HCl b/c mol ratio of HCl : Ba is 2:1
0.179 mol HCl x -533.88 kj/2 mol = -47.7 kJ