## Chemistry and Chemical Reactivity (9th Edition)

(a) $CN^-$ : Cyanide ion. (b) ${SO_4}^{2-}$: Sulfate ion. (c) $F^-$: Fluoride ion.
- To get the formula of a conjugate base, just remove a hydrogen from the acid, and subtract one from the charge: (a) $HCN --\gt CN --\gt CN^-$ (b) $HS{O_4}^- --\gt S{O_4}^{-} --\gt S{O_4}^{2-}$ (c) $HF --\gt F --\gt F^-$ The name: (a) $CN^-$ is an ion formed by the cyano group ($CN^-$), so it is the cyanide ion. (b) $S{O_4}^{2-}$ is an ion formed by the sulfato group, so it is the sulfate ion. (c) $F^-$ is an ion formed by a fluorine atom, so it is the fluoride ion.