Question

What is meant by the conjugate acid-base pair? Find the conjugate acid/base for the following species:

HNO₂, CN^–, HClO₄, F^–, OH^–, `"CO"_3^(2-)`, and S^2–

Answer 1

A conjugate acid-base pair is a pair that differs only by one proton.

The conjugate acid-base for the given species is mentioned in the table below.

Species	Conjugate acid-base
HNO2	`"NO"_2^(-)` (base)
CN–	HCN (acid)
HClO4	`"ClO"_4^(-)` (base)
F–	HF (acid)
OH–	`"H"_2"O" ("acid")//"O"^(2-)`(base)
`"CO"_3^(2-)`	`"HCO"_3^(-)` (acid)
`"S"^(2-)`	`"HS"^(-)` (acid)