Answer
a)$[Al(OH)(H_{2}O)_{5}](OH)_{2}$
The central metal ion is Aluminium(Al) and it is in a $+3$ oxidation state.
b) $[Ni(CO)_{4}]$
The central metal atom is Nickel(Ni) and it is in a $0$ oxidation state.
c) $Na_{3}[CoCl_{6}]$
The central metal ion is cobalt(Co) and it is in a $+3$ oxidation state.
d) $[Co(H_{2}O)_{6}]^{3+}$
The central metal ion is cobalt(Co) and it is in a $+3$ oxidation state.
e) $K[Cr(NH_{3})_{2}(OH)_{2}Cl_{2}]$
The central metal ion is Chromium(Cr) and it is in a $+3$ oxidation state.
f) $[Co(en)_{2}Cl_{2}]$
The central metal ion is cobalt(Co) and it is in a $+3$ oxidation state.
Work Step by Step
a)$[Al(OH)(H_{2}O)_{5}](OH)_{2}$
The central metal ion is Aluminium(Al) and it is in a $+3$ oxidation state.
b) $[Ni(CO)_{4}]$
The central metal atom is Nickel(Ni) and it is in a $0$ oxidation state.
c) $Na_{3}[CoCl_{6}]$
The central metal ion is cobalt(Co) and it is in a $+3$ oxidation state.
d) $[Co(H_{2}O)_{6}]^{3+}$
The central metal ion is cobalt(Co) and it is in a $+3$ oxidation state.
e) $K[Cr(NH_{3})_{2}(OH)_{2}Cl_{2}]$
The central metal ion is Chromium(Cr) and it is in a $+3$ oxidation state.
f) $[Co(en)_{2}Cl_{2}]$
The central metal ion is cobalt(Co) and it is in a $+3$ oxidation state.
