Acid mine drainage (AMD) occurs when geologic deposits containing pyrite (FeS₂) are exposed to oxygen and moisture. AMD is generated in a multistep process catalyzed by acidophilic (acid-loving) bacteria. Balance each step and identify those that increase acidity:(1) FeS₂(s) + O₂(g) → Fe²⁺(aq) + SO₄²⁻(aq) (2) Fe²⁺(aq) + O₂(g) → Fe³⁺(aq) + H₂O(l) (3) Fe³⁺(aq) + H₂O(l) → Fe(OH)₃(s) + H⁺(aq) (4) FeS₂(s) + Fe³⁺(aq) → Fe²⁺(aq) + SO₄²⁻(aq)