JEE Main 2015ChemistryCoordination CompoundsMediumMCQ

JEE Main 2015Coordination Compounds Question with Solution

JEE Main 2015 (11 Apr Online)

Question

When concentrated HCl is added to aqueous solution of CoCl2, its colour changes from reddish pink to deep blue. Which complex ion gives blue colour in reaction?

Choose an option

Show full solutionCorrect option: D
Correct answer
DCoCl42-

Step-by-step explanation

On addition of conc. HCl. The equilibrium between two coloured Co (II) species can be described by equation

CoH2O6aq2++4Claq-CoCl4aq2-+6H2OPinkBlue

The equilibrium is disturbed by changing the conc. of Cl- ions by addition of conc. HCl in forward direction.
 
     
 

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About this question

This is a previous-year question from JEE Main 2015, covering the Coordination Compounds chapter of Chemistry. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.