Write equilibrium constant expressions for the following reactions. Show how they are related ?
(a) `Na_(2)CO_(3)+HCI hArr NaHCO_(3)+NaCI`
(b) `2Na^(+)+CO_(3)^(2-)+H^(+)+CI^(-)hArr 2Na^(+)+HCO_(3)^(-)+CI^(-)`
(c ) `CO_(3)^(2-)+H^(+)hArr HCO_(3)^(-)`

Explanation

(a) `K_(C_(1)) = ([NaHCO_(3)][NaCI])/([Na_(2)CO_(3)][HCI])`
(b) `K_(C_(2))= ([Na^(+)]^(2)[HCO_(3)^(-)][CI^(-)])/([Na^(+)]^(2)[CO_(3)^(2-)][H^(+)](CI^(-)])`
`= ([HCO_(3)^(-)])/([CO_(3)^(2-)][H^(+)])`
(c ) `K_(C_(3))= ([HCO_(3)^(-)])/([CO_(3)^(2-)][H^(+)])`
`K_(C_(2)= K_(C_(3))`. Expression for (a) like `K_(C_(1))` is in applicable , sine it incorporates [NaCI] whereas NaCI is not involved in the actual reaction (the reaction takes place between ions).