CHAPTER 8 ALCOHOLS Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 101 MCQ PRACTICES 1. Name the compound below. A 3-isopropyl-5-hexanol B 4-isopropyl-2-hexanol C 3-ethyl-2-methyl-5-hexanol D 4-ethyl-5-methyl-2-hexanol 2. A compound with molecular formula C4H10O does not react with potassium permanganate but reacts immediately with Lucas reagent. The possible structural formula for the compound is, A CH CH CH CH OH 3 2 2 2 B 3 2 2 2 ( ) CH CH CH OH C 3 3 ( ) CH COH D 3 2 3 CH CH CH OH CH ( ) 3. Arrange the following compounds in the order of increasing boiling point. I. CH CH CH CH OH 3 2 2 2 II. CH CH CH OH 3 2 2 III. CH CH CH CH CH OH 3 2 2 2 2 IV. CH CH OH 3 2 A IV < I < II < III B IV < II< I < III C I < IV < II < III D I < IV < III < II 4. Which of the following alcohols would react slowest with Lucas reagent? A 3 3 2 ( ) CH CCH OH B 3 2 ( ) CH CHOH C 3 3 ( ) CH COH D 3 2 3 CH CH CH OH CH ( ) 5. Which of the following alkenes is the major dehydration product of 3-methyl-2- butanol? A 2 3 3 CH CHCH CH CH = ( ) B 3 2 3 ( ) CH C CHCH = C 2 3 2 3 CH C CH CH CH = ( ) D CH CH CHCH CH 3 2 3 = 6. All the following compounds decolourise acidified potassium permanganate EXCEPT A CH CH OH 3 2 B C 3 2 ( ) CH CHOH D 7. Which of the following reagent can be used to differentiate 2-butanol from cyclobutanol? A Concentrated H2SO4 B PCC in CH2Cl2 C Alkaline iodine solution D Acidified water 8. Which of the following compound is NOT true? A Alcohol is a polar molecule. B Methanol is the simplest alcohol. C Fermentation can be used to produce ethanol. D Alcohol is less soluble in water as the number of carbon decreases.
CHAPTER 8 ALCOHOLS Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 102 9. Which one of the compounds below will react with its own oxidation product to form a sweet smell liquid? A 1-butanol B 2-butanol C 2-methyl-2-butanol D 3-methyl-2-butanol 10. Which of the following reagents can be used to distinguish between 3-pentanol and 1-pentanol? A Sodium metal B Alkaline iodine solution C Acidified sodium dichromate D Concentrated hydrogen chloride with zinc chloride 11. Suggest structure of A A B C D 12. Which of the following alcohol forms a ketone when oxidised? A 1-butanol B ethanol C 2-propanol D phenol 13. Which alcohol can be used to produce 4- methyl-2-pentene by dehydration? A 4-methyl-1-pentanol B 2-methyl-1-pentanol C 2-methyl-3-pentanol D 1-propanol and 2-propanol 14. The structural formula of an organic compound, B is shown below. Which of the following product is obtained if B is heated strongly with acidified potassium dichromate? A B C D 15. When 1-butanol is treated with reagent C, butanal is formed, and no further oxidation to carboxylic acid occurs. What is reagent C? A Chromic acid B PCC in CH2Cl2 C Concentrated H3PO4 D Acidified KMnO4
CHAPTER 8 ALCOHOLS Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 103 16. The conversion below can be carried out using, A KMnO4 , H+ , Δ B H2O , H+ C KMnO4 ,OH- , cold, diluted D Concentrated H2SO4, Δ 17. The product formed when 3-pentanol reacts with concentrated sulphuric acid is, A H C CHCH CH CH 2 2 2 3 = B CH CH CH CHCH 3 2 3 = C 3 2 3 2 CH CH CH CH ( ) D CH CH CH CH CH 3 2 2 2 3 18. Alcohols with longer carbon chain are slightly soluble in water. Choose the most accurate explanation. A Alcohol with longer carbon chain has a bigger hydrophobic area. B Alcohol with longer carbon chain can form hydrogen bond with water. C Alcohol with longer carbon chain has a bigger hydrophilic area. D Alcohol with longer carbon chain is a non-polar molecule. 19. Choose the product formed when 2- pentanol, CH3CH(OH)CH2CH2CH3 reacts with hot acidified potassium dichromate solution. A 2-pentene B Pentanal C Pentanoic acid D 2-pentanone 20. Choose an alcohol that can be oxidised to 3-methyl-2-butanone, CH3COCH(CH3)2 A 3 3 2 CH CH OH CH CH ( ) ( ) B 3 2 3 2 CH CH C OH CH ( )( ) C 3 2 2 3 CH CH CH OH CH CH ( ) D 3 2 2 3 CH CH OH CH CH CH ( ) 21. Compound X is produced from oxidation of alcohol using pyridinium chlorochromate, PCC. X is A 3-methyl-2-butanone B Ethene C Propanal D Butanoic acid
CHAPTER 9 CARBONYL COMPOUNDS Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 104 CHAPTER 9 CARBONYL COMPOUNDS
CHAPTER 9 CARBONYL COMPOUNDS Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 105 SUBJECTIVE PRACTICES 1. Draw the structural formula for each of the following compounds. a) 2-ethyl-3-methylpentanal b) 4-chloro-2-methyl-3-heptanone c) Acetone d) Acetaldehyde e) 3-methylbutanal f) 2-methyl-3-pentanone g) 3-methyl-1-phenyl-2-butanone h) 2,3-dimethylbutanal ANSWER a) b) c) d) e) f) g) h)
CHAPTER 9 CARBONYL COMPOUNDS Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 106 2. Give IUPAC name for each of the following aldehydes and ketones: a) b) c) d) e) f) ANSWER a) 2-methylbutanal b) 4-chloro-2,4-dimethylhexanal c) 3-bromo-4-methyl-2-pentanone d) Cyclohexanone e) 1-phenyl-1-ethanone f) 1-phenyl-2-propanone 3. Aldehydes and ketones are the oxidation products of primary and secondary alcohol respectively. Give the names of the aldehydes or ketones produced when the following alcohols are oxidised by using a strong oxidising agent. a) CH3CH(OH)CH3 b) CH3CH(CH3)CH2OH c) ANSWER a) 2-propanone b) 2-methylpropanal c) Cyclohexanone
CHAPTER 9 CARBONYL COMPOUNDS Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 107 4. Show how propanal can be synthesized from 1-propanol. ANSWER 5. Show how 2-propanone can be synthesized from 1-propene. ANSWER 6. By using chemical equations, show the reduction of pentanone to 2-pentanol with suitable reducing agent. ANSWER
CHAPTER 9 CARBONYL COMPOUNDS Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 108 7. When 2-propanol reacts with acidified potassium manganate (VII) solution, compound A is formed. a) Draw the structure of A. b) Write the reaction equation between compound A with: i. KCN, H2SO4 ii. I2, OHANSWER a) b) i) b) ii) 8. a) Draw the structure of compound V and X. b) State the type of reaction to the formation of X. ANSWER a) b) Reduction reaction
CHAPTER 9 CARBONYL COMPOUNDS Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 109 9. Write the reaction equation between propanal with a) KCN, H3O + b) 2,4-dinitrophenylhydrazine ANSWER a) b) 10. Compound M, C4H10O gives a positive result when reacted with iodine in alkaline solution. The oxidation of M yields N. a) Draw the structure of M and N. b) Give suitable reagent for the formation of compound N. ANSWER a) b) + + KMnO , H , 4 2 2 7 Δ @ K Cr O , H , Δ 11. A, B and C are isomers with molecular formula C4H8O. When compound A, B and C react with 2,4-dinitrophenylhydrazine. Orange precipitate is formed. Compound B and C give positive result with silver nitrate in aqueous ammonia. Deduce the structure of A, B and C. ANSWER A, B and C contains carbonyl group because all of them react with 2,4-DNPH. B and C are aldehyde because they give positive result with Tollens’ reagent (silver nitrate in aqueous ammonia). A is ketone because it gives negative result with Tollens’ reagent (silver nitrate in aqueous ammonia).
CHAPTER 9 CARBONYL COMPOUNDS Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 110 12. Consider the following reaction scheme. a) Draw the structures of N and give the reagents Q and R. b) Compare the boiling point between M and L. Explain. c) State the observation and write the chemical equation when M reacts with Tollens’ reagent. Suggest one chemical test that can be conducted to confirm the presence of functional groups in M. ANSWER a) + + KMnO , H , 4 2 2 7 Δ @ K Cr O , H , Δ + KCN, H N Q R b) L has higher boiling point than M. This is because, L can form hydrogen bond while M only has van der Waals forces. Hydrogen bond is stronger than van der Waals force. c) Observation: Silver mirror formed. Equation: Chemical test: Brady’s Test
CHAPTER 9 CARBONYL COMPOUNDS Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 111 13. C and D are straight-chain isomeric carbonyl compounds with molecular formula C5H10O. a) Compound C reacts with acidified KMnO4. Write the chemical equation involved. b) Compound D gives yellow precipitate when it reacts with iodine in aqueous sodium hydroxide. Write the chemical equations involved. ANSWER a) b) 14. a) Consider the following compounds: Explain why H reacts with an alkaline solution of iodine whereas J does not. Write the chemical equation for the reaction. b) Suggest the product formed when 2-methylpentanal reacts with KCN, H+ . Write the chemical equation involved. ANSWER a) H contains methyl carbonyl group. Equation: b) Product formed: Equation:
CHAPTER 9 CARBONYL COMPOUNDS Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 112 15. Reactions of acetophenone, T, is shown below. a) Draw the structures of P, Q, S and U. b) Give the reagents of R. c) Suggest a chemical test to differentiate between T and benzaldehyde. State the observation and write the chemical reaction equation. ANSWER a) CHI3 P Q S U b) c) Tollens’ test Reagent: [Ag(NH3)2] + , OHEquations: Observation: Silver mirror formed Equations: Observation: No silver mirror formed
CHAPTER 9 CARBONYL COMPOUNDS Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 113 MCQ PRACTICES 1. Ketones are formed by oxidation of A primary alcohols. B secondary alcohol. C tertiary alcohol. D amines. 2. Which of the following will react with Tollens’ reagent. A CH3CHO B CH3CH2CH3 C CH3COOH D CH3COCH2CH3 3. Which of the following can be used to differentiate butanal and butanone. A Lucas reagent B Tollens’ reagent C Fehling’s solution D Baeyer’s test 4. Which of the following is the functional group of an aldehyde? A COOH B COCl C CHO D COC 5. Which of the following is aldehyde? A HCOH B H3COCH2OCH3 C H3COCH2COCH3 D H3COCH2CH2C6H5 6. Which of the following alcohols can be oxidised to 3-methyl-2-pentanone? A CH3CH2CH(OH)CH3 B CH3CH(OH)CH2CH2CH3 C (CH3)2CCH(OH)CH3 D (CH3)2CHCH(OH)CH2CH3 7. Which of the following reagents can be used to test the presence of methyl carbonyl group? A Tollens’s reagent B Acidified KMnO4 C Alkaline iodine D Silver diamine complex 8. When 1-propanol is treated with reagent X, propanal is formed and no further oxidation to carboxylic acid occurs. What is reagent X? A Concentrated H3PO4 B KMnO4 in H2SO4 C CrO3 in H2SO4 D PCC in CH2Cl2 9. Which of the following can form aldehyde upon controlled oxidation? I. C6H5CH2CH2CH2OH II. CH3CH2CH2OH III. CH3CH2CH(OH)CH3 A I only B I and II C II and III D I, II and III 10. Name the compound below according to IUPAC nomenclature and give the class of the compound. A 4-chloro-6-methylhexanal / aldehyde B 4-chloro-2-methylcyclohexanal/ aldehyde C 4-chloro-2-methylcyclohexanone/ ketone D 4-chloro-6-methylhexanone / ketone
CHAPTER 9 CARBONYL COMPOUNDS Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 114 11. The reaction below can be carried out by using X. A PCC, CH2Cl2 B Concentrated H2SO4, H+ , Δ C KMnO4, OH- , cold D KMnO4, H+ , Δ 12. Compound 2-propanol can be oxidised to propanone by using hot acidified KMnO4 solution. Which of the following reagents can be used to confirm that oxidation has occurred in this reaction? A 2,4-dinitrophenylhydrazine B Tollens’ reagent C Fehling’s solution D Hydrogen cyanide 13. Name the carbonyl compound below according to IUPAC nomenclature. A 3,3-dimethyl-4-phenyl-2-butanone B 4-phenyl-3,3-dimethyl-2-butanone C 3-benzyl-3,3-methyl-2-butanone D 1-phenyl-3,3-dimethyl-2-butanone 14. Which of the following reagents can be used to differentiate between propanal and propanone? A 2,4-dinitrophenylhydrazine B Hydrogen cyanide C Lithium tetrahydridoaluminate (III) D Tollens’ reagent 15. Which of the following can convert CH3(CH2)2CHO to CH3(CH2)2COOH? A PCC, CH2Cl2 B KMnO4, OHC Conc. H2SO4 D Na2Cr2O7, H+ , Δ 16. The reaction between propanal and Tollens’ reagent is a A condensation reaction. B reduction reaction. C elimination reaction. D oxidation reaction. 17. Which of the following compounds will form an orange precipitate when reacted with Brady’s reagent? A CH3COCH2CH3 B CH3COOCH3 C CH3CONH2 D CH3COCl 18. An organic compound, W, forms a yellow precipitate with alkaline iodine solution, but does not react with [Ag(NH3)]+ solution. Compound W may be? A CH3CHO B CH3CH2CH2COCH3 C CH3CH2COCH2CH3 D CH3CH2CHO 19. Which of the following molecular formula represent carbonyl compound? A C4H10O B C4H8O C C4H8O2 D C4H8
CHAPTER 9 CARBONYL COMPOUNDS Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 115 20. Which of the following statements is INCORRECT? A Aldehyde and ketone undergo nucleophilic addition. B Aldehyde and ketone undergo nucleophilic substitution. C Aldehyde and ketone contain polar carbonyl group. D Aldehyde and ketone will give orange precipitate when reacted with Brady’s reagent.
CHAPTER 10 CARBOXYLIC ACIDS Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 116 CHAPTER 10 CARBOXYLIC ACIDS
CHAPTER 10 CARBOXYLIC ACIDS Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 117 SUBJECTIVE PRACTICES 1. Give the IUPAC names for the following carboxylic acids: a) CH3(CH2)5COOH b) c) d) ANSWER a) Heptanoic acid b) Cyclohexanecarboxylic acid c) 6-phenyloctanoic acid d) 3-methylpentanoic acid 2. Draw the structural formula for each of the following compounds: a) 2-hydroxy-2-phenylethanoic acid b) 2-chlorobutanedioic acid c) o-hydroxybenzoic acid ANSWER a) b) c) 3. Which of the following compounds have higher boiling point? Explain. a) butanoic acid or pentanoic acid b) propanoic acid or propane c) ethanol or ethanoic acid
CHAPTER 10 CARBOXYLIC ACIDS Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 118 ANSWER a) Pentanoic acid has higher boiling point than butanoic acid because it has higher molecular mass which results to stronger van der Waals forces than butanoic acid. Hence, more energy is needed to overcome the strong forces between its molecules. b) Propanoic acid has higher boiling point than propane because it has carboxyl group which form stronger hydrogen bond than just weaker van der Waals forces that the propane has. Hence, more energy is needed to overcome the strong forces between its molecules. c) Ethanoic acid has higher boiling point than ethanol because it has carboxyl group which form more and stronger hydrogen bonded dimers compared to hydroxyl group in ethanol. Hence, more energy is needed to overcome the strong forces between its molecules. 4. Which of the following compounds is more soluble in water? Explain. a) butanoic acid or heptanoic acid b) pentane or pentanoic acid c) heptanoic acid or heptanedioic acid d) butanoic acid or butanol ANSWER a) Butanoic acid is more soluble in water than heptanoic acid because it has smaller alkyl group, which means smaller hydrophobic area. This results to stronger interaction with water molecules. b) Pentanoic acid is more soluble in water than pentane because it has carboxyl group which has stronger interaction with water molecules since it can form hydrogen bonds with water molecules. Pentane have weak van der Waals interaction with water molecules. c) Heptanedioic acid is more soluble in water than heptanoic acid because it has more carboxyl groups which can form more hydrogen bonds and has stronger interactions with water molecules. d) Butanoic acid is more soluble than butanol because it has carboxyl functional group which can form more hydrogen bonds with water compared to butanol with hydroxyl group which can form less hydrogen bonds with water. 5. Identify compounds A, B, C and D as well as reagent and condition X in the reaction scheme below: a) b) c)
CHAPTER 10 CARBOXYLIC ACIDS Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 119 ANSWER a) b) c) 6. Write down complete chemical equations for the reactions of 2-methylbutanoic acid with following reagents: a) sodium b) magnesium c) sodium hydroxide, NaOH d) sodium carbonate, Na2CO3 e) sodium hydrogen carbonate, NaHCO3 f) propanol in the presence of sulphuric acid ANSWER a) b) c) d) e)
CHAPTER 10 CARBOXYLIC ACIDS Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 120 f) 7. An organic compound P is an alcohol which reacts with pyridinium chlorochromate in dichloromethane to form compound Q. Then, compound Q is treated with hot acidified potassium chromate to produce compound R. When compound R is reacted with compound P in the presence of concentrated sulphuric acid, compound S as shown below is formed. a) Identify and give the names for compound P, Q and R. b) Write down all the chemical equations involved in this question. ANSWER a) Compound S is an ester. It is produced from the reaction of carboxylic acid and alcohol in the presence of mineral acid. The red part of the ester comes from carboxylic acid, while the green part comes from alcohol. Compound S So, the alcohol P is most likely to have the following structure: Compound P (cyclohexylmethanol) Compound P, a primary alcohol then undergoes oxidation with PCC in CH2Cl2 to form the following aldehyde Q: Compound Q (cyclohexylmethanal) When aldehyde Q is oxidised with hot acidified KMnO4, carboxylic acid R is formed:
CHAPTER 10 CARBOXYLIC ACIDS Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 121 Compound R (cyclohexanecarboxylic acid) b) 8. By referring to the following sequence of reactions: a) Give reasonable structures and IUPAC nomenclature for compound A, B and C. b) Write down the chemical equations for the reactions of C with: i. Mg ii. Na iii. Ethanol, conc. H2SO4 ANSWER a) A: CH3CH2CH2CH2OH (1-butanol) B: CH3CH2CH2CHO (butanal) C: CH3CH2CH2COOH (butanoic acid) b) i. ( ) 2 3 2 2 3 2 2 2 2 2CH CH CH COOH Mg CH CH CH COO Mg H − + + → + ii. 3 2 2 3 2 2 2 1 2 CH CH CH COOH Na CH CH CH COO Na H − + + → + iii. 3 2 2 3 2 3 2 2 2 3 2 H CH CH CH COOH CH CH OH CH CH CH COOCH CH H O heat + + ⎯⎯⎯→ +
CHAPTER 10 CARBOXYLIC ACIDS Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 122 9. Consider the following compounds: a) Give the IUPAC nomenclature for compound D, E and F. b) Which compound has the highest boiling point? Explain. c) Which compound has the highest solubility in water? Explain. d) Suggest a suitable alcohol to synthesise compound D. Write down the chemical equation. e) Reaction of E with propan-2-ol in the presence of mineral acid yield a sweet-smelling liquid. Write down the chemical equation. ANSWER a) D: propanoic acid E: benzoic acid F: pentanoic acid b) Compound E has the highest boiling point because it has the highest molecular mass, which means the strongest van der Waals forces. Hence, highest amount of energy is needed to overcome the strong forces between its molecules. c) Compound D is the most soluble in water because it has the smallest alkyl group which means smallest hydrophobic area. Hence, it has the greatest interaction with water molecules. d) 1-propanol e)
CHAPTER 10 CARBOXYLIC ACIDS Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 123 10. For the following reaction scheme: a) Give the IUPAC name for the carboxylic acid. b) Draw the structures of the product P to T. ANSWER a) 2-phenylethanoic acid b) 11. A sweet-smelling compound V has a molecular formula of C4H8O2 which is produced by reacting compound W and compound X in the presence of mineral acid. Compound W reacted the slowest with Lucas reagent. Compound W reacted with reagent J producing compound Y. The compound Y gives orange precipitate with 2,4-dinitrophenylhydrazine. When compound Y is reacted with reagent K, carboxylic acid X is produced. Give reasonable structures for compounds V, W, X and Y, as well as reagents and conditions J and K. Between compound W and X, which is more soluble in water? Explain.
CHAPTER 10 CARBOXYLIC ACIDS Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 124 ANSWER a) b) Compound X is more soluble than compound Y. This is because X has carboxyl functional group which can form more hydrogen bonds with water compared to Y which only has hydroxyl functional group. 12. With the help of chemical equations, show how acetic acid could be formed from: a) ethanal b) ethene ANSWER a) b) 13. Benzoic acid, LL reacts with magnesium metal to give magnesium benzoate, MM. Acid catalysed esterification of LL with ethanol forms PP. Neutralisation of LL with KOH produces RR. a) Draw the structures of LL, MM, PP and RR. b) State the by-product formed during the reaction that produces MM and PP. ANSWER a) b) By-product formed with MM: H2 By-product formed with PP: H2O
CHAPTER 10 CARBOXYLIC ACIDS Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 125 14. Based on the reaction scheme below: a) Give reagents and conditions for H, J and L. b) Draw the structure of G, M and N. c) Which of the following compounds are more soluble in water? Explain. 3-methylbutanoic acid, benzoic acid ANSWER a) H reagent: PCC in CH2Cl2 J reagent: KMnO4, H+ condition: heat L reagent: potassium b) c) 3-methylbutanoic acid is more soluble in water than benzoic acid because it has smaller hydrophobic area compared to benzoic acid which has huge benzene ring.
CHAPTER 10 CARBOXYLIC ACIDS Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 126 MCQ PRACTICES 1. Which of the following is a carboxylic acid? A CH3COCOCH3 B CH3COCH2OH C HCO2CH(OH)CH3 D CH3CH2CH2COOH 2. What is the IUPAC name for the following compound? A Ethanol B Acetic acid C Propanoic acid D Methanoic acid 3. Give the IUPAC name for the compound below. A Hexanoic acid B 3-methanoic hexanoic acid C 1,2-dimethanoic pentane D 2-ethylpentanoic acid 4. Arrange the following compounds in order of increasing boiling point. I. CH3CH2CH2CH2OH II. CH3CH2COOH III. COOHCH2CH2COOH IV. CH3CH2CH2COOH A I < II < IV < III B III < IV < II < I C II < IV < I < III D I < II < III < IV 5. Which of the following acids is the most soluble in water? A Benzoic acid B Pentanoic acid C Propanoic acid D 1,4-propanedioic acid 6. Compound M reacted with hot acidified potassium permanganate to produce a carboxylic acid. The following compound could potentially be M except... A CH3CH2OH B CHOCH2CH3 C CH2CH(OH)CH2CH3 D CH3CH(CH3)CH2CH2CH2OH 7. Choose the correct compound N based on the following chemical reaction. A C(CH3)3COOH B CH3C(CH3)2CH2OH C CH3C(CH3)(CH3)CH2COOH D CH3CH(CH3)COOH 8. What happen when methanoic acid is treated with sodium metal? A An ester is formed. B Methane is formed. C Methanol is formed. D Hydrogen gas is released. 9. Reaction of propanoic acid with calcium metal yield what product. A H2O B CaOH C CH3CH2COOCa D (CH3CH2COO)2Ca 10. Which of the following alcohols is used in the manufacturing of the following ester? A CH3CH2CH(OH)CH3 B CH3C(CH3)2OH C CH3CH(CH3)CH(OH)CH3 D CH3CH(CH3)CH2CH2OH
CHAPTER 10 CARBOXYLIC ACIDS Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 127 11. Salicylic acid is used in the production of aspirin via the following route: X could be … A CH3OH B CH3CH2COOH C (CH3CO)2O D CH3CO 12. What is the functional group of carboxylic acid? A Carboxyl B Hydroxyl C Carbonyl D Carbon-carbon double bond 13. Which is the correct order of boiling points of carboxylic acids, from the lowest to the highest? A methanoic acid, ethanoic acid, butanoic acid, propanoic acid B methanoic acid, propanic acid, butanoic acid, ethanoic acid C ethanoic acid, methanoic acid, propanoic acid, butanoic acid D methanoic acid, ethanoic acid, propanoic acid, butanoic acid 14. Which of these compounds is the most soluble in water? A Propanol B 1,2-propanediol C Ethanedioic acid D Ethanoic acid 15. The compound with highest boIling point in the following is........... A Butanal B 2-butanone C Butanoic acid D 2-butanol 16. Boiling points of carboxylic acids is higher than those of corresponding alcohols is due to A Strong London dispersion forces B Strong dipole dipole interaction C Strong covalent bond D Strong hydrogen bonded dimer To answer question 17 – 20, consider the following options: A B C D I only I and II II and III I, II and III 17. Choose the correct name(s) for the following compound. I. benzoic acid II. benzenecarboxylic acid III. phenylmethanoic acid 18. Which of the following acid would decolorise acidified KMnO4 solution under a suitable condition? I. propanoic acid II. propanol III. propanal 19. Which forces responsible for differences in boiling point of successive members of carboxylic acids? I. van der Waals II. hydrogen bond III. electrovalent bond 20. In the reaction with carboxylic acids, which of the following reagent(s) would yield water as a by-product? I. sodium hydroxide II. magnesium III. potassium
Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 128 SULIT DK024 Chemistry 2 Semester 2 Session 2022/2023 2 hours DK024 Kimia 2 Semester 2 Sesi 2022/2023 2 jam BAHAGIAN MATRIKULASI MATRICULATION DIVISION PEPERIKSAAN SEMESTER PROGRAM MATRIKULASI MATRICULATION PROGRAMME EXAMINATION JANGAN BUKA KERTAS SOALAN INI SEHINGGA DIBERITAHU DO NOT OPEN THIS QUESTION PAPER UNTIL YOU ARE TOLD TO DO SO
PSPM DK024 SESI 2022/2023 Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 129 Answer all questions. Jawab semua soalan. 1 (a) Based on the following differential rate equation, 4 2 2 2 [ ] [ ] [ ] [ ] 1 1 2 2 d CH d O d CO d H O Rate dt dt dt dt = − = − = + = + Determine the rate of depletion of O2 if the rate of formation of CO2 is 0.72 Ms-1 . [3 marks] (b) The decomposition of acetaldehyde, CH3CHO, to yield methane, CH4 and carbon monoxide, CO, is a second order reaction. The reaction equation is given below. 3 4 CH CHO g CH g CO g ( ) ( ) ( ) → + i. Determine the reaction rate if the concentration of acetaldehyde is 1.75 x 10-3 M and the rate constant for the reaction is 6.72 x 10-6 M-1 s -1 . ii. Predict what would happen to the reaction rate if the concentration of acetaldehyde is double. [4 marks] 2 When 2.05 g of solid naphthalene, C10H8, is burned in a bomb calorimeter, the temperature rises by 16.2 oC. The heat capacity of the calorimeter is 5.00 kJ oC -1 . (a) Determine the enthalpy of combustion of naphthalene. [5 marks] (b) Write the thermochemical equation for the combustion of naphthalene. [2 marks] 3 (a) The structure of compound A is shown below. Redraw the compound, circle and name all the functional groups that exist in compound A. [3 marks] (b) Compound B is a molecule with a molecular formula of C3H8O. It has three structural isomers. Draw all the structural isomers for compound B. [3 marks]
PSPM DK024 SESI 2022/2023 Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 130 (c) Predict the type of reaction for each of the following equations. i) ii) [2 marks] 4 An alkyl radical, C is formed in the monosubstitution reaction of alkane, D, C5H12, with bromine in the presence of sunlight. The structure of alkyl radical, C, is shown below. (a) Draw the structural formula and give the IUPAC name of the alkane D. [2 marks] (b) Reaction of radical C with bromine gas in the propagation step generates a bromine radical. Write the mechanism for this step. [3 marks] 5 (a) 2-methyl-2-pentanol reacts with hot concentrated sulphuric acid solution to produce alkenes E and F as major and minor products respectively. Reaction of E with HBr formed compound G. i. Draw the structures of E, F and G. ii. Name the rule used to identify the formation of G. iii. Write the reaction mechanism for the formation of G. [7 marks] (b) 2-methyl-2-pentene can be differentiated from 2-methylpentane by using dilute alkaline potassium permanganate, KMnO4 solution. i. Name the chemical test. ii. Write the reaction equations and state the observations. [8 marks]
PSPM DK024 SESI 2022/2023 Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 131 6 Based on the reaction scheme below, (a) Draw the structural formulae of J and K. [2 marks] (b) Suggest the reagent and condition of I and II. [2 marks] (c) Explain the function of H2SO4 in the formation of J. [1 marks] (d) Give the name of reaction for the formation of K. [1 marks] (e) Give the IUPAC name for L. [1 marks]
PSPM DK024 SESI 2022/2023 Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 132 7 Compounds M and N are branched alcohols with molecular formula C4H10O. Both compounds are isomers. TABLE 7 shows the results for the chemical reaction of M and N. TABLE 7 Alcohol Observation Lucas reagent Oxidation M Cloudy solution formed immediately. Purple colour solution unchanged. N No cloudy solution formed within 10 minutes. Purple colour solution decolourised. (a) Identify the class of alcohol M and N. [2 marks] (b) Draw the structural formulae of M and N. [2 marks] (c) Write a chemical equation for the reaction of alcohol M with Lucas reagent. [2 marks] (d) State the reagent used for oxidation reaction. [1 marks] (e) Alcohol N does not undergo oxidation reaction. Explain. [1 marks] 8 (a) Give the IUPAC name for the following compounds. i. CH3(CH2)2COCH2CH3 ii. (CH3)2CH(CH2)3CHO [2 marks] (b) Compound P is an isomer of propanone, CH3COCH3. P gives yellow precipitate upon reaction with 2,4-dinitrophenylhydrazine and shows a positive result in Tollens’ test. P can be prepared by oxidation of primary alcohol. i. Identify the functional group for P. ii. Predict the structural formula for P. iii. Write the chemical equation for the preparation of P using an appropriate alcohol. [4 marks]
PSPM DK024 SESI 2022/2023 Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 133 (c) Compound Q reacts with LiAlH4 followed by hydrolysis to give an alcohol, R. Treatment of Q with acidified KCN produces a cyanohydrin, S. The structural formula for compound Q is shown below. i. Draw the structural formulae for R and S. ii. Give a chemical test to differentiate between compound Q and propanone, CH3COCH3. Write the chemical equation and state the observation involved. [7 marks] 9 (a) i. Compare the boiling point of butanoic acid and pentanoic acid. Explain. ii. Ethanoic acid, CH3COOH is soluble in water. Explain. [5 marks] (b) Based on the reaction scheme below, i. Give the IUPAC name for the compound T. ii. Draw the structural formulae of compound T, U, V and W. [5 marks] END OF QUESTION PAPER KERTAS SOALAN TAMAT
Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 134 SULIT DK024 Chemistry 2 Semester 2 Session 2021/2022 2 hours DK024 Kimia 2 Semester 2 Sesi 2021/2022 2 jam BAHAGIAN MATRIKULASI MATRICULATION DIVISION PEPERIKSAAN SEMESTER PROGRAM MATRIKULASI MATRICULATION PROGRAMME EXAMINATION JANGAN BUKA KERTAS SOALAN INI SEHINGGA DIBERITAHU DO NOT OPEN THIS QUESTION PAPER UNTIL YOU ARE TOLD TO DO SO
PSPM DK024 SESI 2021/2022 Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 135 Answer all questions. Jawab semua soalan. 1 (a) Structural formula of compound A is given as follows. i. Draw the skeletal structure of A. ii. State the number of primary (1o ), secondary (2o ) and tertiary (3o ) carbon(s) present in compound A. [4 marks] (b) Theanine is an amino acid found in green tea. The structure of theanine is given below. Redraw the structure of theanine. Circle and name the functional groups that exist in theanine. [3 marks] (c) i. Classify the following compounds as saturated or unsaturated hydrocarbon. [2 marks] ii. Identify the following compounds as aliphatic or aromatic hydrocarbon. [2 marks]
PSPM DK024 SESI 2021/2022 Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 136 (d) State the type of reaction for the equations below. i) ii) iii) [3 marks] (e) i. Draw all possible structural isomers of C4H8O. ii. Classify the following pairs as chain, positional or functional group isomer. [3 marks] (f) A haloalkane, (CH3)3CCH2Cl, undergoes a reaction with aqueous sodium hydroxide to produce alcohol. In the intermediate stage, carbocations F and G are formed. i. Explain the type of cleavage involve in the formation of the carbocations F and G. ii. Which carbocation is more stable? Explain. [4 marks]
PSPM DK024 SESI 2021/2022 Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 137 2 (a) Compare the boiling point of 3-methylpentane and 2,2-dimethylbutane. Explain. [2 marks] (b) Heptane are insoluble in water but soluble in CH2Cl2. Explain. [3 marks] (c) The bromination of ethane forms monosubstituted product. Write the reaction mechanism to show the initiation and propagation steps for the above reaction. [3 marks] 3 (a) J is a tertiary alcohol with a molecular formula C4H10O. Dehydration of J produces unsaturated hydrocarbon, 2-methylpropene. i. Draw the structure of J. ii. Write the reaction equation for dehydration of J. iii. The reaction of 2-methylpropene with chlorine in dichloromethane produces K. Write the reaction equation involved. [4 marks] (b) The preparation and reactions of 2-methyl-2-butene are shown in the scheme below. i. State reagents I, II and III. ii. What is the rule used to determine 2-methyl-2-butene as a major product from 2- methyl-2-butanol. iii. Draw the structures of L and M. iv. 2-methyl-2-butene can be distinguished from L by using Baeyer’s test. Write the reaction equations and observations. [10 marks]
PSPM DK024 SESI 2021/2022 Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 138 4 (a) Compare the solubility between CH3CH(OH)CH2OH and CH3CH2CH2OH in water. Explain. [3 marks] (b) 1-butene undergoes hydration with acidified water to produce alcohol N. i. Draw the structural formula and give IUPAC name of compound N. ii. State the rule used for the formation of N. [3 marks] (c) Based on the reaction scheme below: i. Draw the structural formulae of P, Q and R. ii. State the reagents IV and V. [5 marks]
PSPM DK024 SESI 2021/2022 Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 139 5 (a) Consider the following reaction scheme of 3-methylbutanal. i. Draw the structural formulae of S and T. ii. State the reagents VI, VII and VIII. iii. Give the observation for the reaction of 3-methylbutanal with reagent VI. [6 marks] (b) U and W are the carbonyl compounds with molecular formula C4H8O. U is positive towards Tollens’ test, while W is not. W gives a yellow precipitate when reacts with alkaline iodine solution. i. Draw the structures of U and W and give the IUPAC names. ii. Write all chemical equations involved and state the observations respectively. [8 marks]
PSPM DK024 SESI 2021/2022 Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 140 6 (a) Compare the boiling point of the following compounds. Explain. [4 marks] (b) Suggest two steps reaction to prepare butanoic acid, CH3CH2CH2COOH, from a suitable alcohol. [4 marks] (c) Reaction scheme of 2-methylpropanoic acid is given below. i. Draw the structures of AA, BB and CC. ii. State reagent IX. [4 marks] END OF QUESTION PAPER KERTAS SOALAN TAMAT
Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 141 SULIT DK024 Chemistry 2 Semester 2 Session 2020/2021 2 hours DK024 Kimia 2 Semester 2 Sesi 2020/2021 2 jam BAHAGIAN MATRIKULASI MATRICULATION DIVISION PEPERIKSAAN SEMESTER PROGRAM MATRIKULASI MATRICULATION PROGRAMME EXAMINATION JANGAN BUKA KERTAS SOALAN INI SEHINGGA DIBERITAHU DO NOT OPEN THIS QUESTION PAPER UNTIL YOU ARE TOLD TO DO SO
PSPM DK024 SESI 2020/2021 Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 142 Answer all questions. Jawab semua soalan. 1 (a) Compound A is given below. i. Draw both the expanded and skeletal structure of A. ii. Circle and name all the functional groups present. iii. State the number of primary (1˚) and secondary (2˚) carbon (s) present in compound A. [7 marks] (b) Ketones with molecular formula C5H10O exist as several structural isomers. i. Draw all possible structures of the isomers. ii. Identify the types of isomerism present by showing the pairs of the isomers. [5 marks] (c) Compound CH3CH2X can undergoes different types of cleavage. Identify the type of cleavage involved and draw the species formed if i. X is more electronegative than carbon, C. ii. X has about the same electronegativity with carbon, C. [5 marks] (d) Classify each of the following carbocations as primary, secondary or tertiary. Arrange them in the descending order of stability. I II III [4 marks]
PSPM DK024 SESI 2020/2021 Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 143 2 Alkanes are also known as paraffin. They are saturated hydrocarbons that consist of single bonds and has no functional group, making it less reactive. (a) Give the IUPAC name for each of the following alkanes. i. ii. [2 marks] (b) Compare the boiling point of the alkanes given below. Explain. [3 marks] (c) Show the mechanism in the propagation step for the chlorination of ethane. [3 marks] 3 The reaction of 2-methyl-2-butanol with reagent I to pproduce alkenes is as follows. (a) i. State reagent I and its condition. ii. Draw the structure of B and give its IUPAC name. iii. State the rule used to determine the major product, B. iv. State the type of reaction involved. [6 marks]
PSPM DK024 SESI 2020/2021 Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 144 (b) The reactions of alkene D are shown in the following scheme. i. Give the IUPAC name for D. ii. Draw the structures for E, F and G. iii. State reagent II. iv. What is the type of reaction when alkene D reacts with reagent II? v. State the observations for the reaction of D to produce F. [8 marks] 4 (a) TABLE 1 shows the data of boiling point and solubility in water for 1-butanol and 1- pentanol. TABLE 1 Physical Properties 1-butanol 1-pentanol Boiling point (˚C) 117.7 138 Solubility in water at 25˚C (g L-1 ) 73.0 22.0 Explain the differences in physical properties of 1-butanol and 1-pentanol in terms of i. boiling point ii. solubility in water [3 marks]
PSPM DK024 SESI 2020/2021 Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 145 (b) J and K are alcohols with molecular formula C4H10O. J gives negative result when reacts with hot acidified potassium permanganate solution while K is positive towards iodoform test. i. Draw all structures for J and K. ii. Write the equation for the reaction of J with sodium metal. iii. J and K can be distinguished by using Lucas test. State the reagents used. Write the reaction equations and give the observations. [8 marks] 5 (a) Name compound L and N according to IUPAC nomenclature. [2 marks] (b) Butanal and butanone are carbonyl compounds. Each compound can be prepared from different classes of alcohols through oxidation reactions. i. Draw the structures of alcohols for the preparation of butanal and butanone respectively. ii. Write the equation for each of the oxidation reaction. [6 marks]
PSPM DK024 SESI 2020/2021 Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 146 (c) Based on the following reaction scheme i. draw the structures of P, Q, R and S. ii. name the chemical test and state the observation for the reaction of acetophenone to produce S and CHI3. [6 marks] 6 (a) Name the following compounds according to the IUPAC nomenclature. [1 mark] (b) Draw the structure of 4-hydroxyhexanoic acid. [1 mark] (c) Compare the solubility in water of the following compounds. Explain. [3 marks]
PSPM DK024 SESI 2020/2021 Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 147 (d) Write the chemical equation for the reaction of propanoic acid, CH3COOH with each of the following reagents. i. Magnesium metal ii. Aqueous potassium hydroxide [2 marks] (e) Preparation of 2,2-dimethylbutanoic acid from the oxidation of alcohol T and aldehyde U are shown in the scheme below. Draw the structures for T and U. [2 marks] (f) Ester can be produced from the reaction between alcohol and carboxylic acid. Write the reaction equation for the formation of the following ester by using suitable alcohol and carboxylic acid. [3 marks] END OF QUESTION PAPER KERTAS SOALAN TAMAT
Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 148 SULIT DK024 Chemistry 2 Semester 2 Session 2019/2020 2 hours DK024 Kimia 2 Semester 2 Sesi 2019/2020 2 jam BAHAGIAN MATRIKULASI MATRICULATION DIVISION PEPERIKSAAN SEMESTER PROGRAM MATRIKULASI MATRICULATION PROGRAMME EXAMINATION JANGAN BUKA KERTAS SOALAN INI SEHINGGA DIBERITAHU DO NOT OPEN THIS QUESTION PAPER UNTIL YOU ARE TOLD TO DO SO
PSPM DK024 SESI 2019/2020 Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 149 Answer all questions. Jawab semua soalan. 1 (a) Name the following compound according to the IUPAC nomenclature. [1 mark] (b) Reaction of methane with bromine is carried out in the presence of sunlight. i. Write a complete chemical equation for this reaction. ii. What is the function of sunlight in this reaction? iii. State the observation for this reaction. iv. Name the type of reaction involved. [4 marks] (c) Arrange the following compounds in order of increasing boiling point. Explain your answer. octane, 2-methylheptane, 2,2,3-trimethylpentane, 2,3-dimethylhexane [5 marks] 2 (a) Name the following compound according to the IUPAC nomenclature. [1 mark] (b) Draw the structural formula for the following compounds. i. 3-chloro-2-iodo-3-methylpentene ii. 1-chloro-1-methylcyclopentene [2 marks]
PSPM DK024 SESI 2019/2020 Lecturer’s Edition DK024 Chemistry 2 Labuan Matriculation College 150 (c) F, C5H12O is an alcohol. Dehydration of F produces 2-methyl-2-butene. i. Draw the structural formula of F. ii. 2-methyl-2-butene undergoes catalytic hydrogenation in the presence of nickel to produce G. Suggest the structural formula of G and write the reaction equation involved. iii. Treatment of 2-methyl-2-butene with bromine in dichloromethane produces H. Draw the structural formula H and write the reaction equation involved. [7 marks] (d) The reaction of 2-methyl-2-pentene are shown in the scheme below. i. Draw the structural formule of J and K. ii. State L and M. iii. 2-methyl-2-pentene also reacts with HBr. State the rule that can be used to predict the product and draw the structural formula of the product. iv. Dehydration of 2-methyl-2-pentanol gives 2-methyl-2-pentene. State the rule that predicts the major product. [8 marks]