NTA Abhyas JEE Main2020Chemistryd and f Block ElementsPractice
Which of the following is coloured compound?
Options
- AC u F 2
- BC u I
- CN a C l
- DM g C l 2
Correct answer
A. C u F 2
Step-by-step solution
The d -block elements form coloured compounds. These compounds have ions with unpaired electron in d -subshell. i) Na and Mg belong to s -block , so NaCl and M g C l 2 are colourless compounds. ii) C u F 2 Oxidation state of Cu in C u F 2 is +2 C u 2 + = 1 s 2 , 2 s 2 , 2 p 6 , 3 s 2 , 3 p 6 , 4 s 0 , 3 d 9 ∴ C u F 2 in which Cu has one unpaired electron is coloured. iii ) C u I Oxidation state of Cu in C u I =+1 C u + = 1 s 2 , 2 s 2 , 2 p 6 , 3 s 2 , 3 p 6 , 4 s 0 , 3 d 10 It has no unpaired electron. So, C u I i