Table 1 Homogeneous and heterogeneous equilibria of inorganic Co²⁺ in aqueous medium

Co²⁺ + H₂O ⇌ CoOH⁺ + H⁺

−9.6

Co²⁺ + 2H₂O ⇌ Co(OH)₂^o + H⁺

−18.8

Co²⁺ + CO₃²⁻ ⇌ CoCO₃^o

3.17

Co²⁺ + HCO₃⁻ ⇌ CoHCO₃⁺

1.39

Co²⁺ + HCO₃⁻ ⇌ CoHCO₃⁺

1.39

Co²⁺ + SO₂²⁻ ⇌ CoSO₄^o

2.36

Co²⁺ + Cl⁻ ⇌ CoCl⁺

−0.05

CoO_(s) + H₂O ⇌ Co²⁺ + 2OH⁻

− 14.87

CoCO_3(s) + 2H⁺ ⇌ Co²⁺ + CO_2(g) + H₂O

10.35

CoCO_3(s) ⇌ Co²⁺ + CO₃²⁻

−9.52