What is meant by the conjugate acid-base pair? Find the conjugate acid`//`base for the following species:
`HNO_(2), CN^(Θ), HClO_(4), F^(Θ), overset(Θ)(O)H, CO_(3)^(2-)`, and `S^(2-)`

Explanation

An acid-base pair which differs by a proton is called conjugate acid-base pair.
`HNO_2 : NO_2^(-) , CN^(-) : HCN`
`HClO_4 : ClO_4^(-) , F^(-) ,HF`
`OH^(-) : H_2O` (acid ) or `O^(2-)` (base) , `CO_3^(2-) : HCO_3^-`
`S^(2-) : HS^-`