a)  $\underset{\text{zasada 1}}{N{O}_2^{-}}+\underset{\text{kwas 2}}{\mathrm{HCl}}\rightleftarrows \underset{\text{kwas 1}}{HN{O}_2}+\underset{\text{zasada 2}}{C{l}^{-}}$  

b)  $\underset{\text{zasada 1}}{HP{O}_4^{2-}}+\underset{\text{kwas 2}}{\mathrm{HClO}}\rightleftarrows \underset{\text{kwas 1}}{H_{2}P{O}_4^{-}}+\underset{\text{zasada 2}}{Cl{O}^{-}}$  

c)  $\underset{\text{kwas 1}}{H_{2}S{O}_3}+\underset{\text{zasada 2}}{H{S}^{-}}\rightleftarrows \underset{\text{zasada 1}}{HS{O}_3^{-}}+\underset{\text{kwas 2}}{H_{2}S}$