hydroxide exposed in air

Hydroxides can have few reactions like these:

(1) Hydroxides have a reaction with carbon dioxide in OH- mole:CO2 mole = 2:1 to form 　 water and carbonate:
　 2 OH- + CO2 -> H2O + CO3 2-

(2) Hydroxides have a reaction with extra carbon dioxide to form hydrogencarbonate:
　 CO2 + OH- -> HCO3-

(3) Hydroxides have a reaction with sulphur dioxide in OH- mole:SO2 mole = 2:1 to form 　 water and sulphite:
　 2 OH- + SO2 -> H2O + SO3 2-
(4) Hydroxides have a reaction with extra sulphur dioxide to form hydrogensulphite:
　 SO2 + OH- -> HSO3-

Because there is little carbon dioxide, sulphur dioxide, etc. So, there are some reactions.


P.S: Sulphur = Sulfur.