The IUPAC name of the complex $[\mathrm{Ag}(\mathrm{H}{}_2\mathrm{O}){}_2][\mathrm{Ag}(\mathrm{CN}){}_2]$ is:

Solution & Explanation

\textbf{Answer:} (D) diaquasilver(I) dicyanidoargentate(I). \textbf{Solution:} The salt $[\mathrm{Ag}(\mathrm{H}{}_2\mathrm{O}){}_2][\mathrm{Ag}(\mathrm{CN}){}_2]$ contains a complex cation and a complex anion; in nomenclature the cation is named first, then the anion. Cation $[\mathrm{Ag}(\mathrm{H}{}_2\mathrm{O}){}_2]{}^{+}$: two aqua ligands → diaqua; silver with charge balance gives Ag in oxidation state $+1$. As a cation the metal keeps its English name: diaquasilver(I). Anion $[\mathrm{Ag}(\mathrm{CN}){}_2]{}^{-}$: two cyanido ligands → dicyanido; Ag is again $+1$. Because it is an anionic complex, the metal takes the -ate suffix using the Latin stem argent-: dicyanidoargentate(I). Combining cation then anion gives diaquasilver(I) dicyanidoargentate(I), option (D). (Both Ag centres are $+1$, ruling out the (II) options.)