Answer:
a. Na₂[Zn(OH)₄]
b. [Co(Cl)₂(en)₂]NO₃
c. [Pt(H₂O)₃Br]Cl
d. [Pt(NH₃)₃(NO₂)₂]Br₂
Step-by-step explanation:
(a) Sodium tetrahydroxozincate(II)
Zincate(II) indicates the metal is Zn²⁺, tetrahydroxo are 4OH⁻, that is
[Zn(OH)₄]²⁻. As the molecule is a neutral salt of sodium:
Na₂[Zn(OH)₄]
(b) Dichlorobis(ethylenediamine)cobalt(III) nitrate
The metal is Co³⁺, bis(ethylenediamine) are (en)₂ and dichloro are 2 Cl⁻, that is:
[CoCl₂(en)]⁺
The counterion is NO₃⁻, that is:
[CoCl₂(en)₂]NO₃
(c) Triaquabromoplatinum(II) chloride
The metal is Pt²⁺, ligands are 3 H₂O and 1 Br⁻, that is:
[Pt(H₂O)₃Br]⁺
The counterion is Cl⁻:
[Pt(H₂O)₃Br]Cl
(d) Tetra-amminedinitroplatinum(IV) bromide
The metal is Pt⁴⁺, ligands are 2 NO₂⁻ anf 3 NH₃, that is:
[Pt(NH₃)₃(NO₂)₂]²⁺
As counterion is Br⁻ you need 2 Br⁻ for the neutral salt, that is:
[Pt(NH₃)₃(NO₂)₂]Br₂
I hope it helps!