Aldehydes, Ketones & Carboxylic Acids: Class 12 Previous Year Questions

Aldehydes, Ketones & Carboxylic Acids questions asked in CBSE board exams

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1. (a) (i) An organic compound (X) has the molecular formula C5H10O. Draw structures for (X) if it : 3 + 2 (I) does not give Tollen’s test but gives a positive iodoform test. (II) does not give Tollen’s test and iodoform test but undergoes Aldol condensation. (II…
   Board 20265 markslong answer
2. Give reasons for the following : 3  1 (a) Carboxylic acids have higher boiling point than alcohols of comparable molecular masses. (b) Alpha () hydrogens of aldehydes and ketones are acidic in nature. (c) Nucleophilic addition of ammonia and its derivatives …
   Board 20263 marksshort answer
3. (A) (a) How will you convert the following : 3 + 2 (i) Propanone to Propene (ii) Benzoic acid to Benzaldehyde (iii) Benzene to m-Nitroacetophenone (b) (i) Arrange the following compounds in increasing order of their reactivity towards HCN : CH3 CH3 C = O, (CH3…
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4. Write the reaction involved in 1 + 1 + 1 (a) Rosenmund’s reduction (b) Cannizzaro’s reaction (c) Hell – Volhard – Zelinsky reaction
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5. Aspirin is obtained by acetylation of 1 (A) Phenol (B) Salicylaldehyde (C) 2-Hydroxybenzoic acid (D) Benzoic acid
   Board 20261 markMCQ
6. (A)J Explain the following reactions and write chemical equation involved : 3×1=3 (a) Wolff-Kishner reduction (b) Etard reaction (c) Cannizzaro reaction OR (B) Write the structures of A, B and C in the following sequence of reactions : 2 × 1% = 3 SOCl2 H2, Pd-…
   Board 20253 marksshort answer
7. Carry out the following conversions : (A) (a) (2 + 3 = 5) (i) Ethanal to But-2-enal (ii) Propanoic acid to ethane (b) An alkene A with molecular formula C,Hio on ozonolysis gives a mixture of two compounds B and C. Compound B gives positive Fehling test and al…
   Board 20255 markslong answer
8. Would you expect benzaldehyde to be more reactive or less reactive in nucleophilic addition reactions than propanal ? Justify your answer.
   Board 20252 marksshort answer
9. Give IUPAC name of CH, - CH = CH - CHO. 31. (A) (a) (b) Give a simple chemical test to distinguish between propanal and propanone. (c) How will you convert the following : (i) Toluene to benzoic acid (ii) Ethanol to propan-2-ol (iii) Propanal to 2-hydroxy prop…
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10. What will be formed after oxidation reaction of secondary alcohol with chromic anhydride (CrO;) ? (A)Aldehyde (B) Ketone (D) Carboxylic acid (C) Ester
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11. Which functional groups of glucose interact to form cyclic hemiacetal leading to pyranose structure ? (A) Aldehyde group and hydroxyl group at C 4 (B) Aldehyde group and hydroxyl group at C 5 (C) Ketone group and hydroxyl group at C 4 (D) Ketone group and hydr…
    Board 20241 markAssertion-Reason
12. (a) (i) Account for the following : (1) Oxidation of aldehydes is easier as compared to ketones. (2) The alpha ( ) hydrogen atoms of aldehydes are acidic in nature. 24 (ii) {ZåZ{b{IV A{^{H«$`mAm| Ho$ CËnmX {b{IE : (iii) EWoZm°BH$ Aåb Am¡a EoWoZ¡b _| {d^oX H$aZ…
    Board 20245 markslong answer
13. H$m~m}hmBS´>oQ> nm¡Ym| Am¡a àm{U`m| XmoZm| _| OrdZ Ho$ {bE Amdí`H$ hmoVo h¢ & nm¡Ym| _| ñQ>mM© H$s Vah Am¡a àm{U`m| _| ½bmBH$moOZ Ho$ ê$n _| H$m~m}hmBS´>oQ> g§J«hU AUwAm| H$s ^m± H$m~m}hmBS´>oQ>m| H$mo Ob-AnKQ>Z _| CZHo$ ì`dhma Ho$ AmYma na _moZmog¡H¡$amBS>, A…
    Board 20244 marksshort answer
14. Write the chemical equation when : 1+1=2 (a) Butan-2-one is treated with Zn(Hg) and conc. HCl. (b) Two molecules of benzaldehyde are treated with conc. NaOH.
    Board 20242 marksshort answer
15. Which of the following compounds will give a ketone on oxidation with chromic anhydride (CrO3) ? (A) (CH3)2CH CH2OH (B) CH3CH2CH2OH (C) (CH3)3C OH (D) CH3 CH2 CH CH3 | OH 4 3. DNA Ho$ VrZ KQ>H$m| _| go Xmo KQ>H$ -D-2- jmaH$ hmoVo h¢ & Vrgam KQ>H$ h¡ : (A) EoS>…
    Board 20241 markMCQ
16. The formation of cyanohydrin from an aldehyde is an example of : (A) nucleophilic addition (B) electrophilic addition (C) nucleophilic substitution (D) electrophilic substitution
    Board 20241 markMCQ
17. (a) (i) Carry out the following conversions : (1) Ethanal to But-2-en-1-al (2) Propanoic acid to 2-chloropropanoic acid (ii) An alkene with molecular formula C5H10 on ozonolysis gives positive Fehling test and also reacts with iodine and NaOH 2+3=5 OR (b) (i) …
    Board 20235 markslong answer
18. The carbon – oxygen double bond is polarised in aldehydes and ketones due to higher electronegativity of oxygen relative to carbon. Therefore they undergo nucleophilic addition reactions with a number of nucleophiles such as HCN, NaHSO3, alcohols, ammonia deri…
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19. Which of the following does not give aldol condensation reaction ? 1 (a) CH3–CHO (b) (c) (d) CH3COCH3
    Board 20231 markMCQ
20. A{^{H«$`m doJ, BH$mB© g_` _| A{^H$maH$m| H$s gm§ÐVm KQ>Zo AWdm CËnmXm| H$s gm§ÐVm d¥{Õ go g§~§{YV hmoVm h¡ & Bgo {H$gr jU {deof na VmËj{UH$ doJ Ho$ ê$n _| Am¡a {H$gr XrK© g_` A§Vamb _| Am¡gV doJ go àX{e©V {H$`m Om gH$Vm h¡ & A{^{H«$`m doJ Ho$ J{UVr` {Zê$nU H$m…
    Board 20234 marksshort answer

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