Module 4 Problem Set_ Principles of Organic Chemistry with Lab-2021-Gallaher

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12/14/23, 8:43 PM Module 4 Problem Set: Principles of Organic Chemistry with Lab-2021-Gallaher https://portagelearning.instructure.com/courses/1430/quizzes/35810?module_item_id=151520 1/13 Module 4 Problem Set Due No due date Points 10 Questions 13 Time Limit None Attempt History Attempt Time Score LATEST Attempt 1 16,103 minutes 10 out of 10 Score for this quiz: 10 out of 10 Submitted Nov 2 at 1:31am This attempt took 16,103 minutes. 0 / 0 pts Question 1 Your Answer: Explain the difference between alkyl and aryl halides. Alkyl: Alkyl halides are aliphatic hydrocarbons that possess one or more halogen atom substituents. Aryl: Aryl halides are aromatic hydrocarbons (benzene rings) with one or more halogen atoms attached to the ring. Answer: Alkyl halides are aliphatic hydrocarbons that possess one or more halogen atom substituents. Aryl halides are aromatic hydrocarbons (benzene rings) with one or more halogen atoms attached to the ring.

12/14/23, 8:43 PM Module 4 Problem Set: Principles of Organic Chemistry with Lab-2021-Gallaher https://portagelearning.instructure.com/courses/1430/quizzes/35810?module_item_id=151520 2/13 0 / 0 pts Question 2 Your Answer: On a piece of paper, write a structure corresponding to each of the following and then generate the IUPAC name for each. a. A primary alkyl chloride with MF C H Cl b. A secondary alkyl iodide with MF C H I c. A tertiary alkyl bromide with MF C H Br 3 7 4 9 5 11 A. 1-chloropropane B. 2-iodobutane C. 2-bromo-2-methylbutane 0 / 0 pts Question 3 Name each of the following using the IUPAC systematic nomenclature methodology. Include stereochemical designations of cis or trans where appropriate.

12/14/23, 8:43 PM Module 4 Problem Set: Principles of Organic Chemistry with Lab-2021-Gallaher https://portagelearning.instructure.com/courses/1430/quizzes/35810?module_item_id=151520 3/13 A. trans-1-chloro-2-methy Correct! Correct! B. 4-bromo-1,2-dichlorohe Correct! Correct! C. 2-fluoro-3-methylbutan Correct! Correct! D. 1,3-dichlorobenzene Correct! Correct! E. 2-iodo-2-methyloctane Correct! Correct! 0 / 0 pts Question 4 Classify each alkyl halide as primary, secondary, or tertiary:

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12/14/23, 8:43 PM Module 4 Problem Set: Principles of Organic Chemistry with Lab-2021-Gallaher https://portagelearning.instructure.com/courses/1430/quizzes/35810?module_item_id=151520 4/13 Your Answer: A. secondary B. tertiary C. secondary D. primary Answer: A. Secondary B. Tertiary C. Secondary D. Primary 0 / 0 pts Question 5 Your Answer: Define the terms nucleophile , substrate , and leaving group . The substrate is the molecule on which the substitution occurs. A leaving group is an atom (or group of atoms) that is replaced by another when the substitution occurs A nucleophile is a chemical species that seeks positive charge (nucleo = nucleus/positive charge, phile = love).

12/14/23, 8:43 PM Module 4 Problem Set: Principles of Organic Chemistry with Lab-2021-Gallaher https://portagelearning.instructure.com/courses/1430/quizzes/35810?module_item_id=151520 5/13 Answer: The substrate is the molecule on which the substitution occurs. A leaving group is an atom (or group of atoms) that is replaced by another when the substitution occurs. A nucleophile is a chemical species that seeks positive charge (nucleo = nucleus/positive charge, phile = love). 0 / 0 pts Question 6 Your Answer: Explain why nucleophiles attack the carbon that bears the halogen atom during a nucleophilic substitution reaction of an alkyl halide. The oxygen molecule has a + charge, which the nucleophiles love. Answer: The polarization of the carbon-halogen bond in an alkyl halide makes the carbon electron-deficient and, as a result, gives it a slight positive charge (as well as a slight negative charge on the halogen correspondingly). The nucleophile (positive- charge lover) is thus attracted to the electron-deficient carbon.

12/14/23, 8:43 PM Module 4 Problem Set: Principles of Organic Chemistry with Lab-2021-Gallaher https://portagelearning.instructure.com/courses/1430/quizzes/35810?module_item_id=151520 6/13 0 / 0 pts Question 7 Your Answer: In each of the following reactions, identify the nucleophile , substrate , and leaving group . Nucleophile Substrate Leaving Group a) 1.__________ 2.__________ 3._________ b) 4.__________ 5.__________ 6.__________ 1. 1-bromobutane 2. Br 3. Hydroxide ion 4. 2-iodo-2-methylproane 5. I 6. Cyanide

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12/14/23, 8:43 PM Module 4 Problem Set: Principles of Organic Chemistry with Lab-2021-Gallaher https://portagelearning.instructure.com/courses/1430/quizzes/35810?module_item_id=151520 7/13 Answer: Nucleophile Substrate Leaving Group a) 1. Hydroxide ion 2. 1-bromobutane 3. Bromine b) 4. Cyanide ion 5. 2-iodo-2- methylpropane 6. Iodine 0 / 0 pts Question 8 Your Answer: Explain in a few sentences how elimination mechanisms are different than substitution pathways. Elimination vs substitution: In elimination the halogen acts as a base instead of a nucleophile Answer: In an elimination reaction, the nucleophile acts as a base (instead of a nucleophile) and removes a β-hydrogen from a carbon adjacent to the carbon bearing the halogen. The base/nucleophile removes the hydrogen as H+, and the electrons from the C-H bond come down to eliminate (kick off) the halogen by forming a C=C bond. The product of an elimination is an alkene . 0 / 0 pts Question 9

12/14/23, 8:43 PM Module 4 Problem Set: Principles of Organic Chemistry with Lab-2021-Gallaher https://portagelearning.instructure.com/courses/1430/quizzes/35810?module_item_id=151520 8/13 Your Answer: Classify each solvent listed as being protic or aprotic . i. Water (H O) ii. Methanol (CH OH) iii. Acetone (CH C=OCH ) iv. DMSO (dimethylsulfoxide) (CH SOCH ) 2 3 3 3 3 3 i. aprotic ii. protic iii. aprotic iv. protic Answer: i. Protic ii. Protic iii. Aprotic iv. Aprotic 0 / 0 pts Question 10 Label each of the following characteristics as being associated with either the S 1 or S 2 substitution mechanism type: Characteristic S 1 or S 2? The reaction happens in a series of steps. 1._______ N N N N

12/14/23, 8:43 PM Module 4 Problem Set: Principles of Organic Chemistry with Lab-2021-Gallaher https://portagelearning.instructure.com/courses/1430/quizzes/35810?module_item_id=151520 9/13 Your Answer: The nucleophile “attacks” from the backside of the C- L bond. 2._______ There is no inversion of tetrahedral geometry at the leaving group carbon . 3._______ Analogous to a gust of wind turning an umbrella inside out, the orientation of the groups that remain attached to the leaving group carbon “flip” (or invert) when the substitution occurs. (Inversion) 4._______ The reaction occurs in a single step . 5._______ The leaving group leaves first . 6._______ Typically associated with bulky substrates (tertiary) 7._______ Typically associated with non-bulky substrates (methyl/primary) 8._______ 1. Sn1 2. Sn1 3. Sn1 4. Sn2 5. Sn2 6. Sn1 7. Sn2 8. Sn1

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12/14/23, 8:43 PM Module 4 Problem Set: Principles of Organic Chemistry with Lab-2021-Gallaher https://portagelearning.instructure.com/courses/1430/quizzes/35810?module_item_id=151520 10/13 Answer: Characteristic S 1 or S 2? The reaction happens in a series of steps. 1. S 1 The nucleophile “attacks” from the backside of the C-L bond. 2. S 2 There is no inversion of tetrahedral geometry at the leaving group carbon . 3. S 1 Analogous to a gust of wind turning an umbrella inside out, the orientation of the groups that remain attached to the leaving group carbon “flip” (or invert) when the substitution occurs. (Inversion) 4. S 2 The reaction occurs in a single step . 5. S 2 The leaving group leaves first . 6. S 1 Typically associated with bulky substrates (tertiary) 7. S 1 Typically associated with non-bulky substrates (methyl/primary) 8. S 2 N N N N N N N N N N 0 / 0 pts Question 11 How many different alkene products could be formed if elimination occurred on each of the following alkyl halide substrates? Do not take E/Z stereoisomers into account. Only consider the different constitutional isomers that can form .

12/14/23, 8:43 PM Module 4 Problem Set: Principles of Organic Chemistry with Lab-2021-Gallaher https://portagelearning.instructure.com/courses/1430/quizzes/35810?module_item_id=151520 11/13 Your Answer: Two 0 / 0 pts Question 12 Fill in the blanks of the following statements that describe the reactivity pattern associated with each subclass of alkyl halide substrate . A. A primary alkyl halide (RCH X) will react by a(n) _1.___ pathway if a good nucleophile (examples include I , Br , RS , NH , or CN ) is used. There will be increasing amounts of 2. product from a(n) 3. pathway as the basicity of the nucleophile increases (examples include HO , RO ). No S 1 or E1 pathways are possible for primary substrates. 2 - - - 3 - - - N

12/14/23, 8:43 PM Module 4 Problem Set: Principles of Organic Chemistry with Lab-2021-Gallaher https://portagelearning.instructure.com/courses/1430/quizzes/35810?module_item_id=151520 12/13 Your Answer: B. A secondary alkyl halide (R CHX) – while 4._____mechanistic pathways are possible, typically these substrates will react by both ______ _5.______ (when weak bases are used) and 6. (when strong bases are used) pathways to give a mixture of substitution and elimination products. C. A tertiary alkyl halide (R X) will react by a(n) ______ 7. ________ pathway when a strong and/or bulky base is used as the nucleophile. When a weak nucleophile is used (or under acidic conditions), a mixture of substitution and elimination products will form by 8. No 9. pathway is available for tertiary substrates. 2 3 1. S 2 2. elimination 3. E2 4. four 5. product 6. E2 7. E2 8. S 1 9. SN2 N N

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12/14/23, 8:43 PM Module 4 Problem Set: Principles of Organic Chemistry with Lab-2021-Gallaher https://portagelearning.instructure.com/courses/1430/quizzes/35810?module_item_id=151520 13/13 Answer: A. A primary alkyl halide (RCH X) will react by an 1. S 2 pathway if a good nucleophile (examples include I , Br , RS , NH , or CN ) is used. There will be increasing amounts of 2. elimination product from an 3. E2 pathway as the basicity of the nucleophile increases (examples include HO , RO ). No S 1 or E1 pathways are possible for primary substrates. B. A secondary alkyl halide (R CHX) – while 4. all four mechanistic pathways are possible, typically these substrates will react by both 5. S 2 (when weak bases are used) and 6. E2 (when strong bases are used) pathways to give a mixture of substitution and elimination products. C. A tertiary alkyl halide (R X) will react by an 7. E2 pathway when a strong and/or bulky base is used as the nucleophile. When a weak nucleophile is used (or under acidic conditions), a mixture of substitution and elimination products will form by 8. S 1 and E1 mechanisms. No 9. S 2 pathway is available for tertiary substrates. 2 N - - - 3 - - - N 2 N 3 N N 10 / 10 pts Question 13 Your Answer: As a reminder, the questions in this review quiz are a requirement of the course and the best way to prepare for the module exam. Did you complete all questions in their entirety? yes Quiz Score: 10 out of 10