Which of the following may need to be balanced using the ion-electron method ?
(A)BaCl2 + Al2(SO4)3 → AlCl3 + BaSO4 (B)H+ + OH- → H2O (C)NaOH + H3PO4 → Na2HPO4 + H2O (D)C2H2(g) + N2O(g) → CO2(g) + H2O(g) + N2(g)
D