Explain why the compounds of copper (II) are coloured, but those of zi

1.	Explain why the compounds of copper (II) are coloured, but those of zinc are colourless.
Answer» i. The electronic configuration of Cu: [Ar] 3d¹⁰ 4s¹ and Cu²⁺: [Ar] 3d⁹ . In copper (II) compounds, Cu²⁺ ions have incompletely filled 3d-orbital (3d⁹). ii. The presence of one unpaired electron in 3d-orbital results in d-d transition due to which, Cu²⁺ ions absorb red light from visible spectrum and emit blue light. Therefore, copper (II) compounds are coloured. iii. In case of zinc, the electronic configuration is Zn: [Ar] 3d¹⁰4s² and Zn²⁺: [Ar] 3d¹⁰. iv. Since 3d subshell is completely filled and there are no unpaired electrons, d-d transition is not possible and hence, Zn²⁺ ions do not absorb radiation in visible region. Therefore, the compounds of zinc are colourless.

Explain why the compounds of copper (II) are coloured, but those of zinc are colourless.

Answer»

i. The electronic configuration of Cu: [Ar] 3d¹⁰ 4s¹ and Cu²⁺: [Ar] 3d⁹ .

In copper (II) compounds, Cu²⁺ ions have incompletely filled 3d-orbital (3d⁹).

ii. The presence of one unpaired electron in 3d-orbital results in d-d transition due to which, Cu²⁺ ions absorb red light from visible spectrum and emit blue light. Therefore, copper (II) compounds are coloured.

iii. In case of zinc, the electronic configuration is Zn: [Ar] 3d¹⁰4s² and Zn²⁺: [Ar] 3d¹⁰.

iv. Since 3d subshell is completely filled and there are no unpaired electrons, d-d transition is not possible and hence, Zn²⁺ ions do not absorb radiation in visible region. Therefore, the compounds of zinc are colourless.

Discussion

No Comment Found

Related InterviewSolutions

What were the two main occupations of the Rig Vedic Aryans?
Name the two political institutions which exercised check on the powers of the King in the Rig Vedic period.
What w’as the position of women in the Rig Vedic age ?
Describe the social life of the Rig Vedic Aryans with reference to the following: (a) The Family Structure (b) Position of Women (c) Varna System
With reference to the following explain the main features of the Rig Vedic Economy: (a) Agriculture (b) Domestication of Animals (c) Trade Transactions, Crafts and Transportation
Mention any two archaeological sources to reconstruct the later Vedic Age.
Mention any two of the Ashrams in the life of a man in Aryan society.
What information do we gather from the later Vedic literature in respect of: (a) Spread of Vedic Civilization to many New Regions. (b) Role of Iron in later Vedic Economy.
Mention briefly the rituals and sacrifices of the later Vedic Aryans?
What is the message of the Bhagavad Gita?