D-And F-Block Elements Ques 305
Question: Of the ions $ Z{{n}^{2+}}, $ $ N{{i}^{2+}} $ and $ C{{r}^{3+}} $
[atomic number of $ Zn=30, $ $ Ni=28, $ $ Cr=24 $ ] [MP PET 1996]
Options:
A) Only $ Z{{n}^{2+}} $ is colourless and $ N{{i}^{2+}} $ and $ C{{r}^{3+}} $ are coloured
B) All three are colourless
C) All three are coloured
D) Only $ N{{i}^{2+}} $ is coloured and $ Z{{n}^{2+}} $ and $ C{{r}^{3+}} $ are colourless
Show Answer
Answer:
Correct Answer: A
Solution:
$ N{{i}^{2+}} $ and $ C{{r}^{2+}} $ are coloured.
But $ Z{{n}^{2+}} $ is colourless because of absence of unpaired $ {{e}^{-}} $ .
