Question

Match the complex ions given in column I with their colour given in column II and mark the appropriate choice.

Column I (Complex ion)		Column II (Colour)
$(A)$	$[Co F_{6}]^{3-}$	(i)	Blue-green
(B)	$[Co (NH_{3})_{6}]^{3+}$	(ii)	Pale yellow
(C)	$[Co (H_{2}O ) _{6}]^{3+}$	(iii)	Green
(D)	$[Co (CN)_{6}]^{3-}$	(iv)	Yellow-orange

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

Answer 1

Answer: (A)

$\left[ CoF _{6}\right]^{3-} \Rightarrow $ Green.
$\left[ Co \left( NH _{2}\right)\right]^{3+} \Rightarrow $ Yellow-Orange.
$\left[ Co \left( NH _{2}\right)_{6}\right]^{3+} \Rightarrow $ Yellow-Orange.
$\left[ Co \left( H _{2} O \right)_{6}\right]^{3+} \Rightarrow $ Blue Green.
$\left[ Co ( CN )_{6}\right]^{3-} \Rightarrow $ Pale Yellow.