JEE Main 202621 JanuaryEvening Shift
- Exam
- JEE Main
- Year
- 2026
- Date
- 21 January
- Shift
- Evening Shift
- Subject
- Chemistry
- Chapter
- d and f Block Elements
JEE Main 2026 · 21 January · Evening Shift · Chemistry · d and f Block Elements
On heating a mixture of common salt and K_ 2 Cr_ 2 O_ 7 in equal...
On heating a mixture of common salt and in equal amount along with concentrated 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:
Options
- A
- B
- C
- D
Correct answer
C.
Step-by-step solution
When a mixture of NaCl and K₂Cr₂O₇ is heated with concentrated H₂SO₄, the dichromate ion oxidizes chloride ions. The reaction produces chromyl chloride (CrO2Cl), which is a volatile deep-red colored gas. The dichromate ion contains chromium in the +6 oxidation state. In the reaction, the dichromate is reduced and chloride is oxidized, but the chromium in the product remains in the +6 oxidation state as CrO2Cl (or as CrO2⁺ in ionic form). The gas evolved is CrO2Cl with chromium in the +6 oxidation state