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JEE Main 2021 · ChemistryMultiple choiceSingle correctEasyRecall

JEE Main 27 August 2021, Shift 2, Chemistry Q50

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

The addition of dilute NaOH to

\mathrm{Cr^{3+}}

salt solution will give :

(1)a solution of $\mathrm{[Cr(OH)_4]^{-}}$
(2)precipitate of $\mathrm{Cr(OH)_3}$ Official answer
(3)precipitate of $\mathrm{Cr_2O_3(H_2O)_n}$
(4)precipitate of $\mathrm{[Cr(OH)_6]^{3-}}$

Official answer

Option 2

NTA final key.

Chapter: The d- and f-Block Elements
Topic: Cation Analysis
Idea tested: Group III Hydroxides

Same idea in other shifts

Asked 2× in all

4 Apr 2024, Shift 1 · Q72In the precipitation of the iron group (III) in qualitative analysis, ammonium chloride is added before adding ammonium hydroxide to :MediumSingle correct

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.