H2SO4 будет реагировать с KOH, Fe(OH)2, BaCl2, Na2S.

С KOH:
Molecular equation: 2H2SO4 + 2KOH -> K2SO4 + 2H2O
Ionic equation: 2H⁺ + SO4²⁻ + 2K⁺ + 2OH⁻ -> 2K⁺ + SO4²⁻ + 2H2O
Net ionic equation: 2H⁺ + 2OH⁻ -> 2H2O

С Fe(OH)2:
Molecular equation: H2SO4 + Fe(OH)2 -> FeSO4 + 2H2O
Ionic equation: 2H⁺ + SO4²⁻ + Fe²⁺ + 2OH⁻ -> Fe²⁺ + SO4²⁻ + 2H2O
Net ionic equation: 2H⁺ + 2OH⁻ -> 2H2O

С BaCl2:
Molecular equation: H2SO4 + BaCl2 -> 2HCl + BaSO4
Ionic equation: 2H⁺ + SO4²⁻ + Ba²⁺ + 2Cl⁻ -> 2HCl + BaSO4
Net ionic equation: 2H⁺ + SO4²⁻ -> BaSO4

С Na2S:
Molecular equation: H2SO4 + Na2S -> Na2SO4 + H2S
Ionic equation: 2H⁺ + SO4²⁻ + 2Na⁺ + S²⁻ -> 2Na⁺ + SO4²⁻ + H2S
Net ionic equation: 2H⁺ + S²⁻ -> H2S