Table 3 Reaction equations for the soluble particles and their molar Gibbs free energy values (Zhang 2008; Liang 2007).
Oxides | Chemical reaction equations |  | \( \Delta_{r} G_{m}^{\varTheta } (298.16 \rm {K}) \) (kJ mol−1) |
|---|---|---|---|
Alkaline oxides | \( {\text{CaO}}(s) + {\text{H}}_{ 2} {\text{O}} \to {\text{Ca}}^{{ 2 { + }}} (aq) + 2{\text{OH}}^{ - } (aq)\) | (3) | − 26.76 |
\( {\text{Ca}}^{2 + } (aq) + 2{\text{OH}}^{ - } (aq) \to {\text{Ca(OH)}}_{2} (s)\) | (4) | − 30.00 | |
\( {\text{MgO}}(s) + {\text{H}}_{ 2} {\text{O}} \to {\text{Mg}}^{2 + } (aq) + 2{\text{OH}}^{ - } (aq) \) | (5) | − 37.79 | |
\( {\text{Mg}}^{2 + } (aq) + 2{\text{OH}}^{ - } (aq) \to {\text{Mg(OH)}}_{2} (s) \) | (6) | − 76.45 | |
Acid oxides | \( {\text{SiO}}_{2} (s) + {\text{H}}_{ 2} {\text{O}} + {\text{OH}}^{ - } (aq) \to {\text{SiO(OH)}}_{3}^{ - } (aq)\) | (7) | − 26.25 |
\( {\text{Al}}_{ 2} {\text{O}}_{ 3} (s) + 3{\text{H}}_{ 2} {\text{O}} + 2{\text{OH}}^{ - } (aq) \to 2{\text{Al(OH)}}_{4}^{ - } (aq) \) | (8) | − 41.86 |