a) BaCl₂

1. Ba(OH)₂ + 2 HCl  BaCl₂ + 2 H₂O

2. Ba + 2 HCl  BaCl₂ + H₂

3. BaO + + 2 HCl  BaCl₂ + H₂O

4. Ba + Cl₂ BaCl₂

b) AgNO₃

1. AgOH + HNO₃ AgNO₃ + H₂O

2. Ag₂O  + 2 HNO₃ 2 AgNO₃ + H₂O

3. N₂O₅ + 2 AgOH  2 AgNO₃ + H₂O

4. Ag₂O