JEE Main 2015Chemistryd and f Block ElementsHardMCQ

JEE Main 2015 — d and f Block Elements Question with Solution

JEE Main 2015 (10 Apr Online)

Question

An aqueous solution of a salt X turns blood red on treatment with SCN- and blue on treatment with K4FeCN6 , X also gives a positive chromyl chloride test. The salt X is:

Choose an option

Show full solutionCorrect option: A
Correct answer
AFeCl3

Step-by-step explanation

FeCl 3 + 3 SCN aq - ⇌ Fe SCN 3 + 3 Cl - Blood red

4 FeCl 3 + 3 K 4 Fe CN 6 → 1 2 KCl + Fe 4 Fe CN 6 Prussian blue

2 FeCl 3 + 3 H 2 SO 4 → Fe 2 SO 4 3 + 6 HCl

K 2 Cr 2 O 7 + 2 H 2 SO 4 → 2 KHSO 4 + 2 CrO 3 + H 2 O

CrO 3 + 2 HCl → CrO 2 Cl 2 + H 2 O Chromyl chloride

CrO 2 Cl 2 +4NaOH→ Na 2 CrO 4 Yellow +2NaCl+2H 2 O

Na 2 CrO 4 + Pb CH 3 COO 2 → PbCrO 4 + 2 CH 3 COONa Yellow ppt.

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About this question

This is a previous-year question from JEE Main 2015, 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.