Question

Specify the oxidation numbers of the metals in the following coordination entities:
(i) $\left[Co\right(H_{2}O\left)\right(CN\left)\right(en{)}_2{]}^{2+}$ (ii) $\left[CoB{r}_2\right(en{)}_2{]}^{+}$ (iii) $[PtC{l}_4{]}^{2-}$ (iv) $K_3\left[Fe\right(CN{)}_6]$ (v) $\left[Cr\right(N{H}_3{)}_{3}C{l}_3]$

Answer 1

Let X be the oxidation number of metal in the complex.
(i) $X+0+(-1)+2\left(0\right)=+2X=+3$
(ii) $X+2(-1)+2\left(0\right)=+1X=+3$
(iii) $X+4(-1)=-2X=+2$
(iv) $3(+1)+X+6(-1)=0X=+3$
(v) $X+3\left(0\right)+3(-1)=0X=+3$