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Chromyl chloride, brown ring and ring tests

37 questions on Chromyl chloride, brown ring and ring tests from the Qualitative Analysis: Anions chapter: 7 NEET level, 11 JEE Main, 19 JEE Advanced. Each one opens with its answer and solution.

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The deep red vapours obtained when a chloride is heated with K2Cr2O7 and concentrated H2SO4 consist of NEET level
The brown ring formed at the junction of the two layers in the nitrate ring test is due to the complex NEET level
Orange-red chromyl chloride vapours are absorbed in aqueous NaOH. The colour of the solution formed is NEET level
Sodium iodide solution is shaken with a little chlorine water and carbon tetrachloride. The lower organic layer becomes NEET level
Which of the following chlorides, when heated with solid K2Cr2O7 and concentrated H2SO4, does NOT give red vapours of chromyl chloride? JEE Main level
Which of the following correctly gives the sum of all the stoichiometric coefficients (reactants and products, smallest whole numbers) in the balanced equation ... JEE Main level
To a freshly prepared solution of FeSO4, dilute acetic acid is added and then the test solution; a brown colour appears immediately, without any concentrated su... JEE Main level
Assertion (A): Mercury(II) chloride does not give the chromyl chloride test. Reason (R): HgCl2 is a covalent compound and does not furnish free Cl- ions to the ... JEE Main level
Match Column I (species) with Column II (colour). Column I: P. CrO2Cl2 vapour; Q. [Fe(H2O)5NO]^2+; R. Na2CrO4 solution; S. Fe4[Fe(CN)6]3. Column II: 1. yellow; ... JEE Main level
Which of the following ions interfere with the brown ring test for nitrate (that is, give a brown ring or a coloured vapour/layer that masks it) if not removed ... JEE Main level
In the chromyl chloride test, K2Cr2O7 + 4NaCl + 6H2SO4 -> 2CrO2Cl2 + 2KHSO4 + 4NaHSO4 + 3H2O. When 0.50 mol of K2Cr2O7 reacts completely, the amounts of NaCl co... JEE Main level
Chlorine water is added to potassium iodide solution containing chloroform. The violet colour of the chloroform layer first deepens and then disappears when exc... JEE Advanced level
A red-orange vapour obtained from a salt, K2Cr2O7 and concentrated H2SO4 is passed into NaOH solution to give a yellow solution Y. Acidification of Y with dilut... JEE Advanced level
In the nitrate ring test, the brown species [Fe(H2O)5NO]^2+ is best described by treating NO as the nitrosonium ligand NO+. Assuming the complex is high spin, t... JEE Advanced level
A solution contains both bromide and nitrate and nitrate is to be detected by the brown ring test. Bromide must first be removed as a precipitate without adding... JEE Advanced level
Which statements about chromyl chloride, CrO2Cl2, and its formation in the chromyl chloride test are correct? One or more options may be correct. JEE Advanced level
Which of the following observations on warming the sodium salt with concentrated H2SO4 (with copper turnings for nitrate) are correct? One or more options may b... JEE Advanced level
In the brown ring test, 3Fe^2+ + NO3^- + 4H+ -> 3Fe^3+ + NO + 2H2O. A mixture of 2.28 g of FeSO4 and 1.01 g of KNO3 is treated in excess dilute acid with the re... JEE Advanced level
The chromyl chloride test for chloride uses solid K2Cr2O7 and concentrated H2SO4. The orange-red vapours formed are of: NEET level
The brown ring formed in the test for nitrate is due to the complex ion: NEET level
A solid is warmed with ethanol and concentrated H2SO4 and the vapour is ignited. It burns with a green-edged flame. The anion present is: NEET level
Orange-red vapours from the chromyl chloride test are passed into aqueous NaOH to give a yellow solution. The solution is acidified with acetic acid and lead ac... JEE Main level
A small amount of each of the following solids is heated with K2Cr2O7 and concentrated H2SO4. Which gives orange-red chromyl chloride vapours? JEE Main level
Select all correct statements about the ring test for borate (boric acid) and the confirmatory tests. JEE Main level
Aqueous FeSO4 is added to a solution of a sodium salt followed by dilute (not concentrated) acetic acid; a brown colouration appears immediately. The anion is: JEE Main level
Assertion: Chromium keeps its +6 oxidation state in the chromyl chloride test with NaCl, whereas with NaI under the same conditions it is reduced to Cr(III). Re... JEE Advanced level
In the brown ring test, nitrate is first reduced to NO by Fe^2+ in acid, and the NO then combines with further Fe^2+ to form [Fe(H2O)5NO]^2+. For each mole of n... JEE Advanced level
Match the species (List I) with the description (List II). List I: P [Fe(H2O)5NO]^2+, Q CrO2Cl2, R Fe4[Fe(CN)6]3, S Na4[Fe(CN)5NOS]. List II: 1 dark blue, conta... JEE Advanced level
Sodium nitroprusside, Na2[Fe(CN)5NO], gives a purple colour with sulphide. Treating NO as NO+, the oxidation state of Fe in nitroprusside and the number of unpa... JEE Advanced level
In [Fe(H2O)5(NO)]^2+, the brown ring complex, treat NO as NO+ and water as a weak-field ligand (high spin). The oxidation state of Fe and the spin-only magnetic... JEE Advanced level
A white salt X gives a brick-red flame. Its aqueous solution gives a white curdy precipitate with AgNO3 that dissolves in dilute ammonia, and a white precipitat... JEE Advanced level
Select all correct statements about the chromyl chloride test. JEE Advanced level
Select all correct statements about the brown ring test for nitrate (take NO as NO+ in the complex). JEE Advanced level
Select all correct statements about sodium nitroprusside Na2[Fe(CN)5NO] as a reagent (take NO as NO+). JEE Advanced level
Prussian blue, Fe4[Fe(CN)6]3, is formed from Fe^3+ and [Fe(CN)6]^4-. Assume the 4 outer iron ions are Fe(III), N-bonded and high spin, and the 3 inner iron ions... JEE Advanced level
Anhydrous borax, Na2B4O7, is warmed with excess ethanol and concentrated H2SO4. Assuming complete conversion, the number of B(OC2H5)3 molecules formed per formu... JEE Advanced level
A 2.000 g salt sample contains 52.0% NaCl by mass, the rest being inert. It is heated with excess solid K2Cr2O7 and concentrated H2SO4 (K2Cr2O7 + 4NaCl + 6H2SO4... JEE Advanced level