MolSynapse / Question bank / Aldehydes, Ketones and Carboxylic Acids / Oxidation and reduction of carbonyls (Clemmensen, Wolff-Kishner, Tollens, Fehling)

Oxidation and reduction of carbonyls (Clemmensen, Wolff-Kishner, Tollens, Fehling)

28 questions on Oxidation and reduction of carbonyls (Clemmensen, Wolff-Kishner, Tollens, Fehling) from the Aldehydes, Ketones and Carboxylic Acids chapter: 6 NEET level, 8 JEE Main, 14 JEE Advanced. Each one opens with its answer and solution.

Practice this topic All Aldehydes, Ketones and Carboxylic Acids topics

Which of the following does NOT reduce Tollens reagent? NEET level
Conversion of C=O into CH2 by Clemmensen reduction uses NEET level
A carbonyl compound is converted to the corresponding alkane by heating with hydrazine and potassium hydroxide in ethylene glycol. This reaction is called NEET level
The red precipitate formed when an aliphatic aldehyde is warmed with Fehling solution is NEET level
Propanal, CH3CH2CHO, is reduced with LiAlH4 in dry ether followed by aqueous work-up. The product is NEET level
Schiff reagent (decolourised magenta) is restored to a pink colour by NEET level
Which of the following gives a negative result with Fehling solution when warmed? JEE Main level
Which of the following ketones gives a silver mirror with Tollens reagent? JEE Main level
Phenyl methyl ketone, C6H5COCH3, is treated with a peroxy acid such as CH3CO3H (Baeyer-Villiger oxidation). The major product is JEE Main level
But-2-enal, CH3CH=CHCHO, is treated with aluminium isopropoxide in excess propan-2-ol (Meerwein-Ponndorf-Verley reduction) and then hydrolysed. The product is JEE Main level
Cyclohexanol is heated with aluminium tert-butoxide in excess propanone. This Oppenauer oxidation gives JEE Main level
Pentan-2-one, CH3COCH2CH2CH3, is oxidised with hot alkaline KMnO4 and the mixture is acidified. By Popoff rule (the carbonyl group stays with the smaller alkyl ... JEE Main level
But-2-enal, CH3CH=CHCHO, is hydrogenated with excess H2 over Ni catalyst. The product is JEE Main level
Which statement about hydride reducing agents is correct? JEE Main level
Ethyl 4-oxopentanoate, CH3COCH2CH2COOC2H5, is to be converted to ethyl pentanoate, with the ester group remaining intact. The most suitable reagent set is JEE Advanced level
5-Hydroxy-5-methylhexan-2-one, CH3COCH2CH2C(CH3)2OH, is to be reduced so that the ketone carbonyl becomes CH2. Which reagent choice and product are correct? JEE Advanced level
Phenyl methyl ketone is treated successively with (i) NaBH4 in methanol, (ii) excess I2 and NaOH with warming, and (iii) dilute HCl. The organic acid formed is JEE Advanced level
Propanone is reduced with magnesium amalgam in benzene followed by water to give P. P is heated with concentrated H2SO4 to give Q (pinacol-pinacolone rearrangem... JEE Advanced level
Three colourless liquids P, Q and R are acetaldehyde, benzaldehyde and acetone in some order. P gives a red precipitate with Fehling solution and a yellow preci... JEE Advanced level
Butan-2-one is oxidised by hot alkaline KMnO4, followed by acidification, according to Popoff rule (the carbonyl group stays with the smaller alkyl group). The ... JEE Advanced level
1-(4-Methylphenyl)ethan-1-one is subjected to Wolff-Kishner reduction to give X. X is heated with excess alkaline KMnO4 and the mixture is acidified to give Y. ... JEE Advanced level
Formaldehyde reduces excess Tollens reagent completely to CO2 (with 4 mol of silver deposited per mole of HCHO). What mass of silver is deposited by 3.0 g of HC... JEE Advanced level
Which of the following give a silver mirror when warmed with Tollens reagent? JEE Advanced level
Which of the following give a red precipitate with Fehling solution on warming? JEE Advanced level
Ethyl 3-oxobutanoate, CH3COCH2COOC2H5, is treated with different reducing agents under the stated conditions. Which statements are correct? JEE Advanced level
Each of the following reaction sequences is carried out to completion on the starting compound. In which are the final organic products (after acidification whe... JEE Advanced level
In which of the following pairs can the two compounds be distinguished by warming each with Fehling solution? JEE Advanced level
Which statements about the Meerwein-Ponndorf-Verley (MPV) and Oppenauer reactions are correct? JEE Advanced level