List out the wrong among the following according to IUPAC and write the correct formula: (a)`[Zn(OH)_4]K_2` , (b)`[CoCl(NH_3)_4(H_2O)]Cl_2`, (c)`[Ag(CN)_2][Ag(NH_3)_2]` and (d)`[Pt(NH_3)_2Cl(NO_2)]`.

Explanation

Formula (a), (b) and (c ) are wrong and only (d) is the correct formula.
To correct (a) and (c ) formula of cation is to be written first. After correction, the correct formula for (a) and (c ) are `K_2 [ Zn(OH)_4] and [Ag(NH_3)_2] [ Ag (CN)_2]`. To correct (b), ligands are to be in alphabetical order irrespective of charge. After correction, the correct formula of (b) is `[Co(NH_3)_4(H_2O)Cl]Cl_2`.