Given below are two statements : In the light of the above statements, choose the correct answer from the options given below :
- Both Statement I and Statement II are correct
- Both Statement I and Statement II are incorrect
- Statement I is correct but Statement II is incorrect
- Statement I is incorrect but Statement II is correct
Answer
(1) Both Statement I and Statement II are correct
Solution
Statement I: an ion is coloured when it has unpaired d electrons (d–d transition).
Ti4+: 3d0 colourless; V2+: 3d3 violet; Mn2+: 3d5 pink; Fe3+: 3d5 yellow; Cr2+: 3d4 blue
⇒ Both ions coloured in [V2+, Mn2+], [Mn2+, Fe3+] and [V2+, Cr2+] = 3 pairs ⇒ Statement I is correct.
Statement II: La3+ (4f0), Yb2+ ( 4f14), Lu3+ ( 4f14), Ce4+ (4f0), Ac3+ (5f0), Lr3+ ( 5f14)
⇒ No ion has an unpaired electron ⇒ all diamagnetic ⇒ 3 pairs ⇒ Statement II is correct.
Answer: (1)