This quiz works best with JavaScript enabled. Home > Cbse > Class 12 > Science > Chemistry Part Ii > Class 12 Chemistry (Part Ii) Chapter 12 Aldehydes – Quiz 4 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 12 Chemistry (Part Ii) Chapter 12 Aldehydes Quiz 4 (35 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. CH$_{3}$COCl + H$_{2 }$in presence of Pd/BaSO$_{4}$$\rightarrow$ A) CH$_{3}$CHO. B) CH$_{3}$COOH. C) CH$_{3}$COCH$_{3}$. D) CH$_{3}$CH$_{2}$OH. Show Answer Correct Answer: A) CH$_{3}$CHO. 2. Which substance would test positively with 2, 4-DNPH but negatively with Tollens' reagent? A) Propanal. B) Propanone. C) Propanoic acid. D) 1-propanol. Show Answer Correct Answer: B) Propanone. 3. What is the correct formula of the reducing agent used to reduce aldehydes and ketones? A) Li$_{2}$AlH$_{4}$. B) LiAlH$_{2}$. C) LiAlH$_{4}$. D) LiAlH. Show Answer Correct Answer: C) LiAlH$_{4}$. 4. Compare the boiling point of ethanal and ethane. A) Ethane is higher as it is polar with stronger intermolecular forces. B) Ethanal is higher because it is polar with stronger intermolecular forces. C) Ethane is lower because it is polar with weaker intermolecular forces. D) Ethanal is lower because it is polar with weaker intermolecular forces. Show Answer Correct Answer: B) Ethanal is higher because it is polar with stronger intermolecular forces. 5. What is the common name for ethanoic acid? A) Acetic acid. B) Propionic acid. C) Formic acid. D) Butyric acid. Show Answer Correct Answer: A) Acetic acid. 6. When reacted with an oxidising agent, secondary alcohols turn into A) Aldehydes. B) Primary alcohols. C) Ketones. D) Carboxylic acids. Show Answer Correct Answer: C) Ketones. 7. What type of reactions can Grignard reagents undergo to form aldehydes or ketones? A) Decarboxylation reactions with alcohols. B) Electrophilic substitution reactions with alkenes. C) Oxidation reactions with halogens. D) Nucleophilic addition reactions with carbonyl compounds. Show Answer Correct Answer: D) Nucleophilic addition reactions with carbonyl compounds. 8. Which functional group represent the aldehyde group. A) R-OH. B) R-COOH. C) R-CHO. D) R-O-R. Show Answer Correct Answer: C) R-CHO. 9. Fehling's solution will turn: A) Blue-brick red. B) Green-orange. C) Orange-green. D) Brick red-blue. Show Answer Correct Answer: A) Blue-brick red. 10. Aldehyde or ketone to alcohol A) Acidified potassium dichromate, heat and distil. B) KCN followed by dilute sulfuric acid at room temperature. C) Acidified potassium dichromate, heat under reflux. D) NaBH4 in aqueous ethanol at room temperature. Show Answer Correct Answer: D) NaBH4 in aqueous ethanol at room temperature. 11. Tollens' reagent shows the following colour change in a ketone A) Stays blue. B) Blue to brick red. C) Stays colourless. D) Colourless to silver mirror. Show Answer Correct Answer: C) Stays colourless. 12. Which of the following compounds is an aldehyde? A) Methanal. B) Propanone. C) Ethanoic acid. D) Butanone. Show Answer Correct Answer: A) Methanal. 13. Catalyst SnCl / HCl 2 is used in A) Rosenmund's reduction. B) Clemmensen's reduction. C) Stephen's reduction. D) Cannizzaro reaction. Show Answer Correct Answer: C) Stephen's reduction. 14. Which of the following statements concerning hydrogen bond is CORRECT? A) Ketone molecules can hydrogen bond to each other. B) Aldehyde molecules can hydrogen bond to each other. C) Both ketone molecules and aldehyde molecules can hydrogen bond to each other. D) Neither ketone molecules nor aldehyde molecules can hydrogen bond to each other. Show Answer Correct Answer: D) Neither ketone molecules nor aldehyde molecules can hydrogen bond to each other. 15. What charge do the green chromium ions, formed during the reduction of potassium dichromate(VI) ions, have? A) -6. B) +3. C) -3. D) +6. Show Answer Correct Answer: B) +3. 16. Which statements about butanone is correct? A) Butanone can be prepared by reduction of 1-butanol. B) Butanone forms silver mirror with Tollen's reagent. C) Butanone form cloudy solution with Lucas test. D) Butanone forms yellow ppt with iodoform test. Show Answer Correct Answer: D) Butanone forms yellow ppt with iodoform test. 17. The mechanism that you need to learn for aldehydes and ketones is called A) Electrophilic substitution. B) Free radical addition. C) Nucleophilic substitution. D) Nucleophilic addition. Show Answer Correct Answer: D) Nucleophilic addition. 18. Main product formed by a reaction between butanal and Tollen's reagent A) Butanol. B) 1-butene. C) Butanoic acid. D) Butane. Show Answer Correct Answer: C) Butanoic acid. 19. Which of these compounds does not react with Brady's reagent? A) Propanoic acid. B) Propanal. C) Propanol. D) Propanone. Show Answer Correct Answer: C) Propanol. 20. The ketonic fuctional group present in 3-oxobutanal is on ..... carbon atom A) 2. B) 3. C) 1. D) 4. Show Answer Correct Answer: B) 3. 21. Assertion (A):Formaldehyde undergoesAldol condensation.Reason (R):Formaldehyde does not contain an a-hydrogen. A) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A). B) Both Assertion (A) and Reason (R) are true but Reason is not the correct explanation of the Assertion. C) Assertion (A) is true, but Reason (R) is false. D) Assertion (A) is true, but Reason (R) is false. Show Answer Correct Answer: C) Assertion (A) is true, but Reason (R) is false. 22. Arrange the boiling point of the following compounds in increasing order.Ethane, ethanol, ethanal A) Ethane B) Ethanal C) Ethane D) Ethanol Show Answer Correct Answer: C) Ethane 23. LAH cannot be used to convert carboxylic acid to the corresponding aldehyde because A) LAH is not reactive. B) RCOOH is converted to RCOOLi. C) RCOOH is reduced to RCH2OH. D) RCOOH is converted into R2C=O. Show Answer Correct Answer: C) RCOOH is reduced to RCH2OH. 24. What is the name of C$_{4}$$_{ }$H$_{9}$COOH A) Propanoic acid. B) Butanoic acid. C) Methyl butanote. D) Pentanoic acid. Show Answer Correct Answer: D) Pentanoic acid. 25. What is the IUPAC name for the compound with the formula $CH_3COCH_3$ A) Propanal. B) Propanone. C) Butanal. D) Butanone. Show Answer Correct Answer: B) Propanone. 26. Formula of Propanoic acid is A) CH$_{3}$CH$_{2}$COOH. B) HCOOH. C) CH$_{3}$(CH$_{2}$)$_{3}$COOH. D) CH$_{3}$COOH. Show Answer Correct Answer: A) CH$_{3}$CH$_{2}$COOH. 27. Potassium dichromate is an oxidising agent which can be used to completely oxidise an aldehyde. What is the correct formula of potassium dichromate A) KCrO$_{7}$. B) K$_{2}$CrO$_{7}$. C) K$_{}$Cr$_{2}$O$_{7}$. D) K$_{2}$Cr$_{2}$O$_{7}$. Show Answer Correct Answer: D) K$_{2}$Cr$_{2}$O$_{7}$. 28. All of the following reactions are reversible, except? A) Cyanohydrin formation. B) Acetal formation. C) Hydrolysis of Enamine. D) Reduction of an aldehyde via LiAlH4. Show Answer Correct Answer: D) Reduction of an aldehyde via LiAlH4. 29. What is the key step in the ozonolysis of alkenes to form aldehydes or ketones? A) Reduction of the carbon-carbon double bond. B) Cleavage of the carbon-carbon double bond by ozone. C) Addition of water to the double bond. D) Oxidation of the carbon-carbon double bond. Show Answer Correct Answer: B) Cleavage of the carbon-carbon double bond by ozone. 30. Discuss the odor of aldehydes and ketones. A) Aldehydes smell like vinegar. B) Ketones have a foul smell. C) Aldehydes have a strong, pungent odor described as fruity or flowery, while ketones have a sweet, acetone-like smell. D) Aldehydes have a fishy odor. Show Answer Correct Answer: C) Aldehydes have a strong, pungent odor described as fruity or flowery, while ketones have a sweet, acetone-like smell. 31. Which of the following reaction is not shown by acetone? A) Reaction with NaHSO$_{3}$. B) Reaction with Fehling's solution. C) Reaction with Iodine/NaOH. D) Reaction with Sodium nitroprusside. Show Answer Correct Answer: B) Reaction with Fehling's solution. 32. How can carboxylic acids be prepared from nitriles? A) Reduction of nitriles. B) Esterification of nitriles. C) Hydrolysis of nitriles. D) Oxidation of nitriles. Show Answer Correct Answer: C) Hydrolysis of nitriles. 33. What observation indicates a positive Tollen's test? A) Red precipitate. B) Blue solution. C) Bubbling. D) Silver mirror forms on the test tube. Show Answer Correct Answer: D) Silver mirror forms on the test tube. 34. The compound with the highest acidity in the following is A) Benzoic acid. B) 4-methylbenzoic acid. C) 2-nitrobenzoic acid. D) 4-nitrobenzoic acid. Show Answer Correct Answer: D) 4-nitrobenzoic acid. 35. Ketones may be prepared by the oxidation of ..... A) Aldehydes. B) Tertiary alcohols. C) Secondary alcohols. D) Primary alcohols. Show Answer Correct Answer: C) Secondary alcohols. ← PreviousRelated QuizzesScience QuizzesClass 12 QuizzesClass 12 Chemistry (Part Ii) Chapter 12 Aldehydes Quiz 1Class 12 Chemistry (Part Ii) Chapter 12 Aldehydes Quiz 2Class 12 Chemistry (Part Ii) Chapter 12 Aldehydes Quiz 3Class 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