On heating a mixture of common salt and K 2 Cr 2 O 7 in equal amount along with concentrated H 2 SO 4 in a test tube, a gas is evolved. Formula of the gas evolved and oxidation state of the central metal atom in the gas respectively are :

Chemistry · d and f Block Elements

JEE Main 2026 — 21 January, Evening Shift — Question 63

On heating a mixture of common salt and $\mathrm{K}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}$ in equal amount along with concentrated $\mathrm{H}_{2} \mathrm{SO}_{4}$ in a test tube, a gas is evolved. Formula of the gas evolved and oxidation state of the central metal atom in the gas respectively are :

Option A:
$\mathrm{CrO}_{2} \mathrm{Cl}_{2}$ and +5
Option B:
$\mathrm{CrO}_{2} \mathrm{Cl}_{2}$ and +6
Correct
Option C:
$\mathrm{Cr}_{2} \mathrm{O}_{2} \mathrm{Cl}_{2}$ and +6
Option D:
$\mathrm{Cr}_{2} \mathrm{O}_{2} \mathrm{Cl}_{2}$ and +3

Answer: B

Step-by-step solution

$4 \mathrm{NaCl}+\mathrm{K}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}+6 \mathrm{H}_{2} \mathrm{SO}_{4}$ $\longrightarrow 2 \mathrm{KHSO}_{4}+2 \mathrm{CrO}_{2} \mathrm{Cl}_{2}+4 \mathrm{NaHSO}_{4}+3 \mathrm{H}_{2} \mathrm{O}$ (Chromyl chloride) In Chromyl chloride Cr is in +6 oxidation state.

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Exam: JEE Main 2026
Paper: 21 January, Evening Shift
Subject: Chemistry
Chapter: d and f Block Elements
Topic: Compounds of Chromium

Given below are some of the statements about Mn and Mn 2 O 7 . Identify the correct statements A. Mn forms the oxide Mn 2 O 7 in which Mn…

Answer: B

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