JEE Main On 16 April 2018 Question 22
Question: The incorrect statement out of the following is ______________.
Options:
A) A Ferric ion gives blood red colour with potassium thirocyanate
B) $ c{u^{2+}} $ salts give red coloured borax bead test in reducing flame.
C) $ c{u^{2+}} $ ion gives chocolate coloured precipitate with potassium ferrocyanide solution
D) $ C{u^{2+}} $ and $ N{i^{2+}} $ ions give black precipitate with in presence of solution
Show Answer
Answer:
Correct Answer: C
Solution:
$ C{u^{2+}} $ ion does not give chocolate coloured precipitate with potassium ferrocyanide solution instead it forms white precipitate.
The reaction can be as follow:
$ K _4[Fe(CN _6)+2CuSO _4\to [Fe(CN _6)]+2K _2SO _4] $
