Identifiy the conjugate acid base pair for the following reaction in aqueous solution :
`(i) HS^(-)(aq)+HFhArrF^(-)(aq)+H_(2)S(aq)`
`(ii) HPO_(4)^(2-)+SO_(3)^(2-)hArrPO_(4)^(3-)+HSO_(3)`
`(iii) NH_(4)^(+)+CO_(3)^(2-)hArrNH_(3)+HCO_(3)^(-)`

Explanation

`(i) underset("base"(1))(HS^(-))(aq)+underset("acid"(2))(HF)hArrunderset("base"(2))(F^(-)(aq))+underset("acid"(1))(H_(2)S(aq))`
`HS^(-)` and `H_(2)S` are the conjugate pair.
`HF` and `F^(-)` are the conjugate pair.
`(iii) underset("acid"(1))(HPO_(4)^(2-))+underset("base"(2))(SO_(3)^(2-))hArrunderset("base"(1))(PO_(4)^(3-))+underset("acid"(2))(HSO_(3)^(-))`
Conjugate pair of acid and base :
`underset("acid")(HPO_(4)^(2-))hArrH^(+)+underset("base")(PO_(4)^(3-))`
`underset("acid")(HSO_(3)^(-))hArrH^(+)+underset("base")(SO_(3)^(-2))`
`(iii) underset("acid"(1))(NH_(4)^(+))+underset("base"(2))(CO_(3)^(2-))hArrunderset("base"(1))(NH_(3))+underset("acid"(2))(HCO_(3)^(-))`
Conjugate pair of acid and base :
`underset("acid")(NH_(4)^(-))hArrH^(+)+underset("base")(NH_(3))`
`underset("base")(CO_(3)^(2-))`