Class XII Chemistry Important Question Answer ALDEHYDES, KETONES AND CARBOXYLIC ACIDS

1. Name an aldehyde that does not give positive Fehling's test.
2. What is the name given to the compounds containing a hydroxyl and a cyano group on the same carbon atom?
3. Name the product formed when aldehydes or ketones react with hydroxylamine in weakly acidic medium.
4. What is the nature of carbonyl group present in aldehydes & ketones?
5. A compound does not contain a-hydrogen. Will it undergo Aldol-condensation or Cannizaro reaction?
6. Name the electrophile produced in the reaction of benzene with benzoyl chloride in presence of anhydrous AICI,
7. Among aldehydes & ketones, which is more reactive towards nucleophilic addition reaction?
8. Can the carbonyl group present in aldehydes & ketones undergo electrophilic substitution reactions?
9. Which group impart polar nature to aldchydes?
10. What is the product formed when propanone is subjected to Wolff-Kishner reduction?
11. Out of Acctophenone & benzophenone, which give iodoform test?
12. How many sigma bonds are present in carbonyl group?
13. Aldehydes and ketones can be prepared by the addition of ozone followed by hydrolysis in presence
of zinc dust. What is this reaction known as?
14. Out of ketones & aldehydes, which has higher boiling point?
15. What is the directive nature of carbonyl group present on benzene ring?
16. Name the reaction used for the conversion of acid chlorides to corresponding aldehydes.
17. What is the mixture of NaOH & CaO in 3: I known as?
18. What type of ketones undergo iodoform test?
19. Out of formic acid and acetic acid, which is stronger?
20. Which of these will give HVZ reaction : HCOOH or CH₃COOH?
21. Which acid is used in rubber industry for coagulating latex?
22. Name the reagent used to bring this conversion.
       CH₃-COOH -----> CH₃ - CH₂ - OH
23. Carboxylic acids do not give the characteristic reactions of carbonyl group. Name the effect responsible
for this behaviour.
24. Carboxylic acids react with alcohol in presence of small amount of sulphuric acid to form a product
with fruity smell. What is the product known as?
25. Which compound acts as a catalytic poison in Rosenmund reduction?
26. How docs solubility change with inereasing molecular mass in carboxylie acids?
27. Out of methanal and ethanal, which would undergo aldol condensation?

Answer: 

1. Benzaldehyde         2. Cyanohydrins          3. Oxime       4. Polar      5. Cannizzaro reaction  

6. Benzoylium cation. 7. Aldehydes    8. No.   9. Carbonyl group        10. Propane    11. Acetophenone

12. Three   13. Ozonolysis       14. Ketones     15. Meta-directing    16. Rosenmund Reduction 17. Sodalime
18. Methyl ketones     19. Formic acid     20. CH₃-COOH     21. Formic acid  22. Lithium Aluminium Hydride  23. Resonance.   24. Ester  25. Barium sulphate    26. Decreases    27. Ethanal