Question

Match the complexes given in column I with the oxidation states of central metal atoms given in column II and mark the appropriate choice.

Column I (complex)		Column II (Oxidation state of central atom)
$(A)$	$K_{3}[Co(C_{2}O_{4})_{2} Cl_{2}]$	(i)	0
(B)	$[Pt(C_{2}H_{4})Cl_{3}]^{-}$	(ii)	$+1$
(C)	$[Fe(H_{2}O)_{5}NO]SO_{4}$	(iii)	$+3$
(D)	$[Ni(CO)_{4}]$	(iv)	+2

• A. $(A) \to (ii), (B) \to (i), (C) \to (iv), (D) \to (iii)$
• B. $(A) \to (iv), (B) \to (ii), (C) \to (i), (D) \to (iii)$
• C. $(A) \to (iii), (B) \to (iv), (C) \to (ii), (D) \to (i)$
• D. $(A) \to (i), (B) \to (ii), (C) \to (iii), (D) \to (iv)$

Answer 1

Answer: (C)

(A) $K _{3}\left[ CO \left( C _{2} O _{4}\right) Cl _{2}\right]$
$\Rightarrow \left[ CO \left( C _{2} O _{4}\right)_{2} Cl _{2}\right]^{3-}$
$\Rightarrow m -2(2)-2=-3$
$m =3$
(B) $\left[ Pt \left( C _{2} H _{4}\right) Cl _{3}\right]^{-1}$
$m +0-3=-1$
$m =+2$
(C) $\left[ Fe \left( H _{2} O \right)_{5}( NO )\right]^{2+}$
$m +1=2$
$m =1$
$( D ) \quad\left[ Ni ( CO )_{4}\right]$
$= m +0=0$
$m =0$