JEE Main 2017 · ChemistryMultiple choiceSingle correctMediumMulti-step

JEE Main 2 April 2017 (offline), Chemistry Q50

Question 50 of 90 in this shift, Chemistry question 20 of 30.

On treatment of 100 mL of 0.1 M solution of

\mathrm{CoCl_3.6H_2O}

with excess

\mathrm{AgNO_3}

;

1.2\times10^{22}

ions are precipitated. The complex is :

(1) $\mathrm{[Co(H_2O)_6]Cl_3}$
(2) $\mathrm{[Co(H_2O)_5Cl]Cl_2.H_2O}$
(3) $\mathrm{[Co(H_2O)_4Cl_2]Cl.2H_2O}$ Official answer
(4) $\mathrm{[Co(H_2O)_3Cl_3].3H_2O}$

Official answer

Option 3

CBSE answer key (25/04/2017, used for result).

Chapter: Coordination Compounds
Topic: Coordination Isomerism
Idea tested: Precipitation Tests for Ionization Isomers

Same idea in other shifts

Asked 4× in all

6 Apr 2026, Shift 2 · Q71An excess of $\mathrm{AgNO_3}$ is added to 100 mL of a 0.05 M solution of tetraaquadichloridochromium (III) chloride. The number of moles…EasyNumerical value
7 Apr 2025, Shift 1 · Q62An octahedral complex having molecular composition $\mathrm{Co.5NH_3.Cl.SO_4}$ has two isomers A and B. The solution of A gives a white…EasySingle correct
8 Jan 2020, Shift 1 · Q49The volume (in mL) of 0.125 M $\mathrm{AgNO_3}$ required to quantitatively precipitate chloride ions in 0.3 g of…MediumNumerical value

Question text from the official JEE Main paper published by NTA (CBSE ran the 2017 exam); answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 42 of the 174 JEE Main shifts held from 2017 to 2026.