What is meant by the conjugate acid-base pair? Find the conjugate acid/base for the following species:
$HNO_{2}$,$CN^{-}$,$HClO_{4}$,$F^{-}$,$OH^{-}$,$CO_{3}^{2-}$,and $S^{2-}$

(N/A) conjugate acid-base pair is a pair of chemical species that differ by only one proton $(H^{+})$.
When an acid loses a proton,it forms its conjugate base.
When a base gains a proton,it forms its conjugate acid.
The conjugate acid-base pairs for the given species are listed in the table below:

Species	Conjugate Acid/Base
$HNO_{2}$	$NO_{2}^{-}$ (Conjugate Base)
$CN^{-}$	$HCN$ (Conjugate Acid)
$HClO_{4}$	$ClO_{4}^{-}$ (Conjugate Base)
$F^{-}$	$HF$ (Conjugate Acid)
$OH^{-}$	$H_{2}O$ (Conjugate Acid) / $O^{2-}$ (Conjugate Base)
$CO_{3}^{2-}$	$HCO_{3}^{-}$ (Conjugate Acid)
$S^{2-}$	$HS^{-}$ (Conjugate Acid)