Organic Chemistry Past Paper PDF

6/20/24, 7:39 PM Sample Questions - Chapter 28 Organic Chemistry - Shapes, Reactions & Biopolymers Examples of...

6/20/24, 7:39 PM Sample Questions - Chapter 28 Organic Chemistry - Shapes, Reactions & Biopolymers Examples of Multiple Choice Questions 1. Two isomeric forms of a saturated hydrocarbon (a) have the same structure. (b) have different compositions of elements. (c) have the same molecular formula. (d) have a different content of the isotopes of hydrogen. (e) react vigorously with one another. 2. Which of the following hydrocarbons does not have isomers? (a) C7H16 (b) C6H14 (c) C5H10 (d) C4H8 (e) C3H8 3. The name of the alkane isomer of cis-3-hexene is: (a) 2-methylpentane (b) 3-methylpentane (c) n-hexane (d) 2,3-dimethylbutane (e) cyclohexane 4. How many aromatic isomers of dibromobenzene exist? (a) 2 (b) 3 (c) 4 (d) 6 (e) 8 5. Which one of the following compounds is an isomer of CH3CH2CH2CH2OH? https://www.chem.tamu.edu/class/fyp/mcquest/ch28.html 1/6 6/20/24, 7:39 PM Sample Questions - Chapter 28 (a) CH3CH2CH2OH (b) CH3CH(OH)CH3 (c) CH3CH2CH2CHO (Note: This is one way to write an aldehyde.) (d) CH3CH2CH2CH3 (e) none of the above 6. Which of the following compounds is a functional group isomer of C2H5OH, ethanol (ethyl alcohol)? (a) ethanal, CH3CHO (b) acetic acid, CH3COOH (c) diethyl ether, (C2H5)2O (d) dimethyl ether, (CH3)2O (e) propanol, C3H7OH 7. For which of the compounds below are cis-trans isomers possible? CH3CH=CH2 CH3CH=CHCH2CH3 CH3CH=CHCH3 (1) (2) (3) (a) only 2 (b) both 1 and 2 (c) both 2 and 3 (d) all three (e) only 3 8. Which of the following does NOT exhibit geometric isomerism? (Hint: draw them!) (a) 4-octene (b) 2-pentene (c) 3-hexene (d) 2-hexene (e) 1-hexene 9. Which of the following compounds displays optical isomerism? (a) CH2(OH)-CH2(OH) (b) CH3-CHCl-COOH (c) CH2=CHCl (d) CHCl=CHCl (e) CH3-O-C2H5 10. How many isomeric alkanes of the molecular formula C5H12 are there? (a) 1 (b) 2 (c) 3 (d) 4 (e) 5 11. https://www.chem.tamu.edu/class/fyp/mcquest/ch28.html 2/6 6/20/24, 7:39 PM Sample Questions - Chapter 28 How many alcohols are structural isomers with the formula: C5H11OH? (a) 5 (b) 6 (c) 7 (d) 8 (e) 9 12. What is the relationship between the structures shown? (a) structural isomers (b) geometric isomers (c) conformational structures (d) identical structures (e) optical isomers 13. Which of the following statements concerning conformations is (are) TRUE? (1) Ethane has an infinite number of conformations. (2) The eclipsed conformation of a molecule is slightly more stable and energetically favored than the staggered conformation. (3) A conformation is one specific geometry of a molecule. (a) 1 only (b) 2 only (c) 1 and 2 (d) 2 and 3 (e) 1 and 3 14. Which of the following statements is FALSE regarding the reaction between Cl2 and C2H6? (a) It is a substitution reaction. (b) The reaction will give a single product of C2H5Cl. (c) The reaction mechanism involves free radicals. (d) The reaction can be initiated with either sunlight or heat. (e) The first step in the mechanism is the cleavage of the Cl-Cl bond to give chlorine atoms. 15. Which of the following will undergo an addition reaction with chlorine? (a) CH3CH2CH2CH3 (b) CH3CH2CH=CHCH3 (c) C6H6 (d) CH3CH2COOH (e) CH3CH2OH 16. https://www.chem.tamu.edu/class/fyp/mcquest/ch28.html 3/6 6/20/24, 7:39 PM Sample Questions - Chapter 28 What is the expected product formed from the reaction between 2-butene and Cl2? (a) 1-chlorobutane (b) 2-chlorobutane (c) 2,3-dichlorobutane (d) 2,2-dichlorobutane (e) 3,3-dichlorobutane 17. The reaction of ethyne with which of the following gives CH2Br-CHBrCl? (a) HCl, then HBr (b) HCl, then Br2 (c) Cl2, then HBr (d) Cl2, then Br2 (e) H2, then Br2 18. Dehydration of an alcohol leads to the formation of an _____. (a) alkene (b) alkane (c) alkyne (d) alkyl halide (e) aldehyde 19. A reaction in which a carboxylic acid reacts with a base to form a salt and water is called _____. (a) ionization (b) esterification (c) hydrolysis (d) saponification (e) neutralization 20. How many moles of sodium hydroxide will react with one mole of: (a) 5 (b) 4 (c) 3 (d) 2 (e) 1 21. Ethanol can be oxidized stepwise. What is the first stable intermediate product when ethanol is oxidized with a mild oxidation agent? (a) CH3COOH https://www.chem.tamu.edu/class/fyp/mcquest/ch28.html 4/6 6/20/24, 7:39 PM Sample Questions - Chapter 28 (b) CO2 (c) CH3CHO (d) CH3CH2OH (e) CH3OCH3 22. Which of the following alcohols forms a ketone when oxidized? (a) 1-propanol (b) methanol (c) 2-methyl-2-propanol (d) 2-propanol (e) all of the above 23. What is the sum of the coefficients in the balanced equation for the complete combustion of 2- methylbutane? Use smallest whole number coefficients. Do not forget coefficients of 1. (a) 10 (b) 13 (c) 17 (d) 20 (e) 23 24. The organic starting materials for the preparation of an ester could be _______. (a) an acid and an alcohol (b) a ketone and an alcohol (c) an alkane and a ketone (d) only an acid (e) an amine and an acid 25. Hydrolysis (saponification) of a fat would yield ______. (a) water and an alkene (b) ethanol and propanoic acid (c) glycerol and soap (d) ethanol and a soap (e) a triester of glycerol with fatty acids 26. The segment -CH2CH2CH2CH2CH2CH2- represents the polymer named _______. (a) polybutylene (b) polyhexene (c) polypropylene (d) polystyrene (e) polyethylene Answers: 1. (c) 2. (e) 3. (e) 4. (b) 5. (e) 6. (d) 7. (c) 8. (e) 9. (b) 10. (c) 11. (d) 12. (c) 13. (e) 14. (b) 15. (b) 16. (c) 17. (b) 18. (a) 19. (e) 20. (e) 21. (c) 22. (d) 23. (d) 24. (a) 25. (c) 26. (e) https://www.chem.tamu.edu/class/fyp/mcquest/ch28.html 5/6 6/20/24, 7:39 PM Sample Questions - Chapter 28 Click here to return to the top. Choose your next chapter: | Fundamentals of Chemistry | Chemical Formulas & Composition Stoichiometry | Chemical Equations & Rxn Stoichiometry | Types of Chemical Reactions | | Atomic Structure | Chemical Periodicity | Chemical Bonding | Molecular Structure/Covalent Bonding Theories| Molecular Orbital Theory | | Acids/Bases/Salts - Theory & Rxns | Acids/Bases/Salts - Calculations (including balancing redox rxns) | Gases | Solids & Liquids | Solutions | | Thermodynamics | Kinetics | Equilibrium | Aqueous Equilibrium - Acids/Bases/Salts | Aqueous Equilibrium - Buffers & Titrations | | Aqueous Equilibrium - Slightly Soluble Salts | Electrochemistry | Metallurgy | Metal Properties & Rxns | Nonmetals & Metalloids | | Coordination Compounds | Nuclear Chemistry | Organic Chem - Formulas/Names/Properties | Organic Chem - Shapes/Rxns/Biopolymers | To report any corrections, please e-mail Dr. Wendy Keeney-Kennicutt. https://www.chem.tamu.edu/class/fyp/mcquest/ch28.html 6/6