General rules used:
- The CATION is named first, then the ANION.
- Within a coordination sphere, LIGANDS are named in ALPHABETICAL ORDER, then the metal.
- The oxidation state of the metal is written in Roman numerals in brackets.
- If the coordination sphere is an ANION, the metal name takes the suffix '-ate'
(for silver the Latin stem ARGENT- is used, so it becomes 'argentate').

(i) $[Ag(NH_3)_2][Ag(CN)_2]$

Step 1 - Split into ions.
Cation = $[Ag(NH_3)_2]^+$ ; Anion = $[Ag(CN)_2]^-$

Step 2 - Oxidation state of Ag in the cation.
$NH_3$ is neutral, so $x + 2(0) = +1 \Rightarrow x = +1$

Step 3 - Oxidation state of Ag in the anion.
$CN^-$ carries $-1$, so $x + 2(-1) = -1 \Rightarrow x = +1$

Step 4 - Name the cation, then the anion.
Cation: two $NH_3$ = 'diammine', metal Ag(I) = 'silver(I)' $\rightarrow$ diamminesilver(I)
Anion: two $CN^-$ = 'dicyanido', metal in an anion = 'argentate(I)' $\rightarrow$ dicyanidoargentate(I)

IUPAC NAME: DIAMMINESILVER(I) DICYANIDOARGENTATE(I)

(ii) $K_3[Fe(C_2O_4)_3]$

Step 1 - Split into ions.
Cation = $3K^+$ ; Anion = $[Fe(C_2O_4)_3]^{3-}$

Step 2 - Oxidation state of Fe.
Oxalate $C_2O_4^{2-}$ carries $-2$ and is BIDENTATE.
$x + 3(-2) = -3 \Rightarrow x = +3$
(Coordination number of Fe $= 3 \times 2 = 6$.)

Step 3 - Name the ligand and metal.
Three oxalate ligands = 'trioxalato' (or 'tris(oxalato)')
Metal in an anion = 'ferrate(III)'

IUPAC NAME: POTASSIUM TRIOXALATOFERRATE(III)
[also acceptable: potassium tris(oxalato)ferrate(III)]