1. The chemical equation \(Na_2SO_{4(aq)}+BaCl_{2(aq)}→BaSO_{4(s)↓}+2NaCl_{(aq)}\) represents which of the following types of reaction?
2. A single displacement reaction is represented by \(X_{(s)}+2HCl_{(aq)}→XCl_{2(aq)}+H_{2(g)}\). Which of the following(s) could be \(X\).

(i) \(Zn\)
(ii) \(Ag\)
(iii) \(Cu\)
(iv) \(Mg\)

Choose the best pair.