JEE Main 2018Chemistryd and f Block ElementsMediumMCQ

JEE Main 2018 — d and f Block Elements Question with Solution

JEE Main 2018 (16 Apr Online)

Question

The incorrect statement is:

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Show full solutionCorrect option: B
Correct answer
BCu2+ and Ni2+ ions give black precipitate with H2S in presence of HCl solution

Step-by-step explanation

Cu+2 gives black precipitate in presence of dil. HCl Ni+2 ions gives black precipitate in presence of NH4Cl +NH3
with HCl S2- concentration is not just sufficient to overcome the solubility product of NiS.

Cu+2+H2S→dil. HClCu2S↓(black)+2H+

Ni+2+H2S→NH4ClNH4OHNiS↓(black)+2H+
 

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About this question

This is a previous-year question from JEE Main 2018, covering the d and f Block Elements 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.