Question

LIST-I contains metal species and LIST-II contains their properties.

LIST I		LIST II
1	$\left[ Cr ( CN )_6\right]^{4-}$	P	$t_{2 g }$ orbitals contain 4 electrons
2	$\left[ RuCl _6\right]^{2-}$	Q	$\mu($ spin-only $)=4.9 BM$
3	$\left[ Cr \left( H _2 O \right)_6\right]^{2+}$	R	low spin complex ion
4	$\left[ Fe \left( H _2 O \right)_6\right]^{2+}$	S	metal ion in $4+$ oxidation state
		v	$d^4$ species

[Given : Atomic number of $Cr =24, Ru =44, Fe =26$ ]
Metal each metal species in LIST-I with their properties in LIST-II, and choose the correct option

• A. I $\rightarrow$ R, T; II $\rightarrow$ P, S; III $\rightarrow$ Q, T; IV $\rightarrow$ P , Q
• B. I $\rightarrow$ R, S; II $\rightarrow$ P , T; III $\rightarrow$ P, Q; IV $\rightarrow$ Q, T
• C. I $\rightarrow$ P, R; II $\rightarrow$ R, S; III $\rightarrow$ R, T; IV $\rightarrow$ P, T
• D. I $\rightarrow$ Q, T; II $\rightarrow$ S, T; III $\rightarrow$ P, T; IV $\rightarrow$ Q, R

Answer 1

Answer: (A)

(1) $\left[ Cr ( CN )_6\right]^{4-}$
$Cr ^{+2}=[ Ar ]_{18} 3 d ^4 4 s ^0 ;$ low spin complex

$P , R , T$
(2) $\left[ RuCl _6\right]^{2-}$
$Ru ^{+4}=[ Kr ]_{36} 4 d ^4 5 s ^0$; low spin complex

$P , R , S , T$
(3) $\left[ Cr \left( H _2 O \right)_6\right]^{2+}$
$Cr ^{+2}=[ Ar ]_{18} 3 d ^4 4 s ^0$; high spin complex

$ Q,T $
(4) $\left[ Fe \left( H _2 O \right)_6\right]^{2+}$
$Fe ^{+2}=[ Ar ]_{18} 3 d ^6 ;$ High spin complex

$P, Q$