Question

The charges $x$ and $y$ on the following ions are
(i) $[Co(NH_{3})_{2}Cl_{4}]^{x}$
(ii) $[Fe(CN)_{6}]^{y}$
(Oxidation state of Co is $+3$ and $Fe$ is $+2$ in their respective complexes.)

• A. $x=+1, y=-1$
• B. $x=-1, y=+3$
• C. $x=-1, y=-4$
• D. $x=-2, y=-3$

Answer 1

Answer: (C)

In $[Co (NH_{3})_{2}Cl_{4}]^{x}$, oxidation state of Co $= +3$
Hence, $x = + 3 + 2 \times 0 + 4 \times (-1) = -1$
In $[Fe(CN)_{6}]^{y}$, oxidation state of $Fe = +2$
Hence, $y = + 2 + 6 \times (-1) = - 4$