This quiz works best with JavaScript enabled. Home > Cbse > Class 12 > Science > Chemistry Part Ii > Class 12 Chemistry (Part Ii) Chapter 12 Aldehydes – Quiz 2 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 12 Chemistry (Part Ii) Chapter 12 Aldehydes Quiz 2 (60 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. Which is an application of the Tollens' silver mirror test in organic chemistry. A) To determine the acidity of organic compounds. B) To identify the presence of halogens in organic compounds. C) To distinguish between aldehydes and ketones in organic chemistry. D) To measure the boiling point of organic compounds. Show Answer Correct Answer: C) To distinguish between aldehydes and ketones in organic chemistry. 2. HVZ reaction is used to prepare A) Beta Halo acids. B) Ketones. C) Unsaturated acids. D) Alpha Halo acids. Show Answer Correct Answer: D) Alpha Halo acids. 3. Formaldehyde, a common disinfectant, has the formula: A) CH3CHO. B) CH3COOH. C) C2H5OH. D) HCHO. Show Answer Correct Answer: D) HCHO. 4. What is the product of the oxidation of a ketone? A) Aldehyde. B) Carboxylic acid. C) Alcohol. D) Alkene. Show Answer Correct Answer: B) Carboxylic acid. 5. The acid that does not contain carboxylic group is A) Acetic acid. B) Picric acid. C) Oxalic acid. D) Formic acid. Show Answer Correct Answer: B) Picric acid. 6. C$_{6}$H$_{6}$ + CO + HCl$\rightarrow$ A) C$_{6}$H$_{5}$CHO. B) C$_{6}$H$_{5}$COCl. C) C$_{6}$H$_{5}$OH. D) C$_{6}$H$_{5}$Cl. Show Answer Correct Answer: A) C$_{6}$H$_{5}$CHO. 7. Below are the reagents and conditions used for reduction except A) KMnO$_{4}$, H$^{+}$, heat. B) I.LiAlH$_{4}$ ii. H$_{3}$O$^{+}$. C) NaBH$_{4}$, Methanol. D) H$_{2}$, Pt. Show Answer Correct Answer: A) KMnO$_{4}$, H$^{+}$, heat. 8. CH$_{3}$CHO + dil. NaOH$\rightarrow$ A) CH$_{3}$CH$_{2}$CH$_{2}$CHO. B) CH$_{3}$COONa. C) CH$_{3}$CH(OH)CH$_{3}$CHO. D) CH$_{3}$CH$_{2}$OH. Show Answer Correct Answer: C) CH$_{3}$CH(OH)CH$_{3}$CHO. 9. Which reagent is commonly used to convert carboxylic acids into acid chlorides? A) SOCl$_{2}$. B) CL$_{2}$. C) HCl. D) CH$_{3}$Cl. Show Answer Correct Answer: A) SOCl$_{2}$. 10. How can carboxylic acids be reduced to alcohols? A) By exposing them to ultraviolet light. B) By using reducing agents such as lithium aluminum hydride (LiAlH4) or sodium borohydride (NaBH4). C) By heating them at high temperatures. D) By using oxidizing agents such as potassium permanganate (KMnO4). Show Answer Correct Answer: B) By using reducing agents such as lithium aluminum hydride (LiAlH4) or sodium borohydride (NaBH4). 11. When a primary alcohol reacts with acidified dichromate: A) There is a colour change from green to orange. B) There is a colour change from orange to green. C) There is no colour change. D) None of the above. Show Answer Correct Answer: B) There is a colour change from orange to green. 12. Carboxylic acids react with carbonates to release which gas? A) Carbon dioxide. B) Nitrogen. C) Oxygen. D) Hydrogen. Show Answer Correct Answer: A) Carbon dioxide. 13. Which test confirms the presence of carbon dioxide? A) 'Pop' sound with a taper. B) Silver mirror. C) Limewater turning milky. D) Blue to pink litmus. Show Answer Correct Answer: C) Limewater turning milky. 14. Which reagent is used in Fehling's test? A) Silver nitrate and ammonia. B) Fehling's A and Fehling's B. C) Sodium hydroxide only. D) Limewater. Show Answer Correct Answer: B) Fehling's A and Fehling's B. 15. Hydrocarbons are formed when aldehydes and ketones are reacted with amalgamated zinc and conc. HCl. The reaction is called A) Clemmensen reduction. B) Cannizzaro reaction. C) Wolff-Kishner reduction. D) Rosenmund reduction. Show Answer Correct Answer: A) Clemmensen reduction. 16. Tollens' reagent shows the following colour change in an aldehyde A) Blue to brick red. B) Colourless to silver mirror. C) Stays blue. D) Stays colourless. Show Answer Correct Answer: B) Colourless to silver mirror. 17. When reacted with an oxidising agent, primary alcohols initially turn into A) Carboxylic acids. B) Ketones. C) Aldehydes. D) Secondary alcohols. Show Answer Correct Answer: C) Aldehydes. 18. Describe the physical state of carboxylic acids at room temperature. A) Gas. B) Liquid. C) Plasma. D) Solid. Show Answer Correct Answer: B) Liquid. 19. When a secondary alcohol reacts with acidified dichromate: A) The alcohol is oxidised to an aldehyde then a carboxylic acid. B) The alcohol is oxidised to a ketone. C) The alcohol is oxidised to an aldehyde then a ketone. D) The alcohol is oxidised to an aldehyde. Show Answer Correct Answer: B) The alcohol is oxidised to a ketone. 20. Which of these are uses of alcohols? A) Solvents. B) Antiseptic. C) Fuels. D) All of the above. Show Answer Correct Answer: D) All of the above. 21. Which of these compounds does not react with Benedicts reagent? A) Propanoic acid. B) Propanal. C) Propanol. D) Propanone. Show Answer Correct Answer: C) Propanol. 22. If propanal reacts with KCN in acidic conditions, which of the following is true? A) The product is not chiral. B) A racemic mixture of the R and S enantiomers is formed. C) Only the R enantiomer forms. D) Only the S enantiomer forms. Show Answer Correct Answer: B) A racemic mixture of the R and S enantiomers is formed. 23. Which substituent on an unsymmetrical carbonyl group would more rapidly undergo rearrangement in a Baeyer-Villiger Oxidation? A) Primary alkyl group. B) Phenyl group. C) Secondary alkyl group. D) Hydrogen. Show Answer Correct Answer: D) Hydrogen. 24. What charge do the orange potassium dichromate ions have? A) -3. B) -6. C) +6. D) +3. Show Answer Correct Answer: C) +6. 25. Which of the following is a characteristic reaction of carboxylic acids? A) Hydrogenation. B) Dehydration. C) Halogenation. D) Esterification. Show Answer Correct Answer: D) Esterification. 26. What is the observation when Acetone is mixed with Sodium nitroprusside and NaOH? A) Blue ppt. B) White ppt. C) Yellow ppt. D) Ruby red ppt. Show Answer Correct Answer: D) Ruby red ppt. 27. What is the product of ozonolysis of alkenes that contain a double bond adjacent to a carbonyl group? A) Alkane and alkene. B) Ester and amine. C) Alcohol and aldehyde. D) Ketone and carboxylic acid. Show Answer Correct Answer: D) Ketone and carboxylic acid. 28. CH$_{3}$CH=CHCH$_{2}$CH$_{2}$OH $\rightarrow$ CH$_{3}$CH=CHCH$_{2}$COOHThe most suitable reagent for this reaction is A) PCC. B) NaBH$_{4}$. C) H$_{2}$, Pt. D) LiAlH$_{4}$. Show Answer Correct Answer: A) PCC. 29. The general formula for an ester is:- A) ROR. B) RCOR. C) RCOOH. D) RCOOR. Show Answer Correct Answer: D) RCOOR. 30. What is the primary method for the oxidation of primary alcohols to aldehydes? A) CrO3 (chromium trioxide). B) NaBH4 (sodium borohydride). C) PCC (pyridinium chlorochromate) or PDC (pyridinium dichromate). D) KMnO4 (potassium permanganate). Show Answer Correct Answer: C) PCC (pyridinium chlorochromate) or PDC (pyridinium dichromate). 31. Which of the following would undergo Cannizzaro reaction? A) Methanal. B) Cyclohexanone. C) Phenylacetaldehyde. D) Benzophenone. Show Answer Correct Answer: A) Methanal. 32. Which of the following is used in Rosenmund reduction? A) LiAlH$_{4}$. B) H$_{2}$ /Pd-BaSO$_{4}$. C) NaBH$_{4}$. D) Na/Ethanol. Show Answer Correct Answer: B) H$_{2}$ /Pd-BaSO$_{4}$. 33. Carboxylic acids can be prepared by A) Hydrolysis of acid chlorides. B) Hydrolysis of nitriles. C) Oxidation of aldehyldes. D) All of above. Show Answer Correct Answer: D) All of above. 34. Upon oxidation with hot acidified KMnO$_{4, }$ aldehydes turn into ..... A) Ketones. B) Secondary alcohols. C) Carboxylic acids. D) Primary alcohols. Show Answer Correct Answer: C) Carboxylic acids. 35. 2HCHO + conc. NaOH$\rightarrow$ CH$_{3}$OH + HCOONa is A) Cross Aldol condensation. B) Aldol condensation. C) Cannizzaro reaction. D) Rosenmund reduction. Show Answer Correct Answer: C) Cannizzaro reaction. 36. Which reagent is commonly used for the reduction of carboxylic acids to aldehydes? A) NaBH4. B) LiAlH4. C) H2SO4. D) KMnO4. Show Answer Correct Answer: B) LiAlH4. 37. In Fehling's test, which ion is reduced by an aldehyde? A) Cu2+. B) Na+. C) Ag+. D) OH-. Show Answer Correct Answer: A) Cu2+. 38. Iodoform test:Pale yellow ppt2. Fehling's test:No observable change3. 2, 4-DNPH:yellow pptWhich compound will have the above observations? A) CH$_{3}$COOH. B) C$_{6}$H$_{5}$CHO. C) CH$_{3}$CH$_{2}$COCH$_{3}$. D) CH$_{3}$CH$_{2}$CHO. Show Answer Correct Answer: C) CH$_{3}$CH$_{2}$COCH$_{3}$. 39. Acetone reacts with HCN to form a cyanohydrin. It is an example of A) Nucleophilic addition. B) Nucleophilic substituition. C) Electrophilic substituition. D) Electrophilic addition. Show Answer Correct Answer: A) Nucleophilic addition. 40. What is the purpose of adding ammonia in Tollen's test? A) To oxidise the aldehyde. B) To neutralise the solution. C) To produce silver metal. D) To dissolve the brown precipitate. Show Answer Correct Answer: D) To dissolve the brown precipitate. 41. Carboxylic acids can be prepared by the oxidation of: A) Alkenes only. B) Primary alcohols only. C) Aldehydes only. D) All of the above. Show Answer Correct Answer: D) All of the above. 42. Why does propanone not react in Fehling's test? A) It is too volatile. B) It is acidic. C) It is a ketone and does not oxidise easily. D) It reacts too quickly. Show Answer Correct Answer: C) It is a ketone and does not oxidise easily. 43. Benzaldehyde on nitration gives A) O-nitrobenzaldehyde. B) P-nitrobenzaldehyde. C) M-nitrobenzaldehyde. D) Ortho and para dinitrobenzaldehyde. Show Answer Correct Answer: C) M-nitrobenzaldehyde. 44. Which is a test for a C=O? A) Bromine water. B) Acidified potassium dichromate (VI). C) 2, 4-DNPH (Brady's reagent). D) Victor Meyer's test. Show Answer Correct Answer: C) 2, 4-DNPH (Brady's reagent). 45. The boiling point for ethanoic acid is higher than propanol even when both these molecules have the same molecular mass. This is because A) The van der Waals forces between ethanoic acids are stronger. B) Propanol molecules cannot form hydrogen-bonds. C) Ethanoic acids can form dimmers through hydrogen bonding. D) The hydrophobic group is propanol is longer than that of ethanoic acid. Show Answer Correct Answer: C) Ethanoic acids can form dimmers through hydrogen bonding. 46. Which statement correctly compares Fehling's and Tollen's tests? A) Both tests work for ketones. B) Only Fehling's test uses heat. C) Both tests distinguish aldehydes from ketones. D) Both produce a silver mirror. Show Answer Correct Answer: C) Both tests distinguish aldehydes from ketones. 47. Which of the following is mandatory for aldol condensation reaction A) Presence of alpha hydrogen. B) Absence of alpha hydrogen. C) Presence of beta hydrogen. D) Absence of beta hydrogen. E) None of the above. Show Answer Correct Answer: A) Presence of alpha hydrogen. 48. Which substance gives a positive result with Fehling's solution? A) Propanone. B) Ethanol. C) Ethanal. D) Ethanoic acid. Show Answer Correct Answer: C) Ethanal. 49. The reagent that does NOT oxidize aldehyde is A) Alkaline KMnO4. B) Ag2O. C) Acidic K2Cr2O7. D) CrO3. Show Answer Correct Answer: B) Ag2O. 50. The functional group of aldehydes and ketones is A) Carboalkoxy. B) Carboxyl. C) Carbonyl. D) Hydroxyl. Show Answer Correct Answer: C) Carbonyl. 51. On heating compound X with acidified KMnO$_{4}$, compound Y is obtained. Compound Y does not react with Fehling's solution. X and Y are most likely to be, Compound X Compound Y A) CH$_{3}$CH$_{2}$CH$_{2}$OH CH$_{3}$COCH$_{3}$. B) CH$_{3}$COCH$_{3}$ CH$_{3}$COOH. C) CH$_{3}$CH$_{2}$CH$_{2}$OH CH$_{3}$CH$_{2}$CHO. D) CH$_{3}$CH(OH)CH$_{3}$ CH$_{3}$COCH$_{3}$. Show Answer Correct Answer: D) CH$_{3}$CH(OH)CH$_{3}$ CH$_{3}$COCH$_{3}$. 52. Which reaction involves the synthesis of aldehydes or ketones using carbon monoxide and hydrogen chloride? A) Rosenmund reduction. B) Fischer esterification. C) Wittig reaction. D) Grignard reaction. Show Answer Correct Answer: A) Rosenmund reduction. 53. Following reaction between an ylide and an alkyl halide, what other compund would be appropriate to produce a Wittig reagent? A) H30+. B) NaH. C) Na2Cr2O7. D) ROH. Show Answer Correct Answer: B) NaH. 54. Which pairing of test and gas is correct? A) Aldehyde $\rightarrow$ H2. B) Magnesium $\rightarrow$ CO2. C) Carbonate $\rightarrow$ CO2. D) Carbonate $\rightarrow$ H2. Show Answer Correct Answer: C) Carbonate $\rightarrow$ CO2. 55. Which of the following compounds does not contain an-OH group A) Alcohols. B) Aldehydes. C) Carboxylic acid. D) Phenol. Show Answer Correct Answer: B) Aldehydes. 56. When reacted with a strong oxidising agent, aldehydes turn into A) Primary alcohols. B) Carboxylic acids. C) Secondary alcohols. D) Ketones. Show Answer Correct Answer: B) Carboxylic acids. 57. What is the product of the oxidation of propanal? A) Propanoic acid. B) Propanone. C) Propanol. D) Propene. Show Answer Correct Answer: A) Propanoic acid. 58. Tollens reagent will: A) Green-orange. B) Silver mirror disappears. C) Form a silver mirror. D) Orange-green. Show Answer Correct Answer: C) Form a silver mirror. 59. What happens when an aldehyde is oxidized? A) Forms a ketone. B) Forms a halide. C) Forms an alcohol. D) Forms a carboxylic acid. Show Answer Correct Answer: D) Forms a carboxylic acid. 60. The number carboxylic acid group present in the product formed, when cyclohexene is oxidised with KMnO4 and dil.H2SO4 A) 5. B) 2. C) 1. D) 3. Show Answer Correct Answer: B) 2. ← PreviousNext →Related QuizzesScience QuizzesClass 12 QuizzesClass 12 Chemistry (Part Ii) Chapter 12 Aldehydes Quiz 1Class 12 Chemistry (Part Ii) Chapter 12 Aldehydes Quiz 3Class 12 Chemistry (Part Ii) Chapter 12 Aldehydes Quiz 4Class 12 Chemistry (Part Ii) Chapter 10 Haloalkanes And Haloarenes QuizClass 12 Chemistry (Part Ii) Chapter 11 Alcohols QuizClass 12 Chemistry (Part Ii) Chapter 13 Amines QuizClass 12 Chemistry (Part Ii) Chapter 14 Biomolecules QuizClass 12 Chemistry (Part Ii) Chapter 15 Polymers Quiz 🏠 Back to Homepage 📘 Download PDF Books 📕 Premium PDF Books