Which of the following statement(s) is (are) correct when a mixture of NaCl and K2 Cr2 O7 is gen

step 1 In this problem, the reaction will happen something like this. Just look at it carefully. 4 NACL

Which of the following statement(s) is (are) correct when a...

Which of the following statement(s) is (are) correct when a mixture of $\mathrm{NaCl}$ and $\mathrm{K}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}$ is gently warmed with conc. $\mathrm{H}_{2} \mathrm{SO}_{4} ?$ (a) A deep red vapour is evolved (b) The vapours when passed into $\mathrm{NaOH}$ solution gives a yellow solution of $\mathrm{Na}_{2} \mathrm{CrO}_{4}$ (c) Chlorine gas is evolved (d) Chromyl chloride is formed

Which of the following statement(s) is (are) correct when a mixture of $\mathrm{NaCl}$ and $\mathrm{K}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}$ is gently warmed with conc. $\mathrm{H}_{2} \mathrm{SO}_{4} ?$
(a) A deep red vapour is evolved
(b) The vapours when passed into $\mathrm{NaOH}$ solution gives a yellow solution of $\mathrm{Na}_{2} \mathrm{CrO}_{4}$
(c) Chlorine gas is evolved
(d) Chromyl chloride is formed

Labs

Want to see this concept in action?

NEW

Explore this concept interactively to see how it behaves as you change inputs.

View Labs

Key Concepts

Chromyl Chloride Test

This is a qualitative analysis method used to detect the presence of chloride ions. It involves the reaction of a chloride-containing compound with a dichromate salt in the presence of concentrated sulfuric acid, resulting in the formation of chromyl chloride—a volatile, deeply colored compound. The test is significant in analytical chemistry for its distinct visual indication of chloride ions.

Formation and Properties of Chromyl Chloride

Chromyl chloride (CrO2Cl2) is a red, volatile liquid produced when a chloride salt reacts with potassium or sodium dichromate and concentrated sulfuric acid. Its volatility and characteristic red vapour provide a clear visual signal during the test. Understanding its formation is important because it underscores the interplay of redox and acid-base reactions within inorganic systems.

Hydrolysis to Chromate Ion

Upon passing the chromyl chloride vapours into an alkaline solution, a chemical transformation occurs where chromyl chloride is hydrolyzed to produce chromate ions. This results in a yellow solution, a further confirmatory step in the analysis process. The conversion is a key concept in redox reactions and serves as a definitive indicator in the qualitative detection of chloride ions.

Transcript

Please give Ace some feedback