List of top Chemistry Questions on Chemical Reactions of Aldehydes Ketones and Carboxylic Acids asked in CBSE Class XII

Assertion (A) : All aliphatic aldehydes give a positive Fehling’s test.
Reason (R) : Aliphatic aldehydes are reduced by Fehling’s reagent.

Which of the reactions is used in the conversion of a ketone into hydrocarbon ?

Arrange the following compounds in increasing order of their reactivity towards HCN : \[ (CH_3)_3C-CO-CH_3,\qquad CH_3COCH_3,\qquad CH_3CHO \]

Answer the following: \[ (a)(i)\;\text{Write the product(s) when:} \] \[ (I)\;\text{One mol of ethanal is treated with }1\text{ mol of }CH_3OH\text{ in the presence of dry }HCl\text{ gas.} \] \[ (II)\;\text{Benzaldehyde is treated with conc. }NaOH. \] \[ (III)\;\text{Ethanoic acid is heated in the presence of }P_2O_5. \] \[ (a)(ii)\;\text{Write a simple chemical test to distinguish between ethanal and propanal.} \] \[ (a)(iii)\;\text{Write the name of the reagent to transform allyl alcohol to propenal.} \]