Ncert Exercises & Solutions

Match the complex ions give in Column I with the colours given in column II and assign the correct code.

Column I (Complex ion)	Column II (Colour)
A. $[Co {({NH}_{3})}_{6}]^{3 +}$	1. Violet
B. $[Ti {(H_{2} O)}_{6})]^{3 +}$	2. Green
C. ${[Ni (H_{2} O_{6}]}^{2 +}$	3. Pale blue
D. ${[Ni {(H_{2} O)}_{4} (en)]}^{2 +}$	4. Yellowish orange

Codes:

Options:	A	B	C	D
1.	2	3	4	1
2.	3	1	5	2
3.	5	4	3	2
4.	4	3	2	1

Hint: The colour of a compound depends on $∆_{o}$ value

The Colour of the coordination compound is closely related to the CFSE of the coordination compound.

Depending upon the CFSE of given coordination compounds Correct matching will be as follows

Column l (Complex ion)	Column l (Colour)
A. $[Co {({NH}_{3})}_{6}]^{3 +}$	1. Yellowish orange
B. $[Ti {(H_{2} O)}_{6})]^{3 +}$	2. Pale blue
C. ${[Ni (H_{2} O_{6}]}^{2 +}$	3. Green
D. ${[Ni {(H_{2} O)}_{4} (en)]}^{2 +}$	4. Violet

Hence, option fourth is the correct answer.