A student was about to turn in the products he had obtained from the reaction of HI with 3,3,3-trifluoropropene when he realized that the labels had fallen off his flasks and he did not know which label belonged to which flask. His friend reminded him of the rule that says the electrophile adds to the sp 2 carbon bonded to the most hydrogens. In other words, he should label the flask containing the most product 1,1,1-trifluoro-2-iodopropane and label the flask containing the least amount of product 1,1,1-trifluoro-3-iodopropane. Should he follow his friend’s advice?

Welcome back, everyone. A student was tasked to react hydrochloric acid with or for the muscle pump one in. And his teacher asked him to identify the major product he was choosing between one chloral 44 dimethyl pens and four chloro 22 dimethyl pens. His friend suddenly told him that the electro adds to the SP two carbon with a greater number of hydrogens ignoring stereo chemistry. What should be the correct identification of the major product? And we are given four answer choices. A one chloral 44 dimethyl pens B four chloral 22 dimethyl pens C both have equal amounts and D none of the above. So let's consider this reaction. The starting material is a penne derivative. Specifically, we're going to draw a five member chain, the bond is between carbons one and two and carbon four contains two metal groups. So that's how our starting material and we're adding hydrochloric acid. Let's consider the mechanism of the reaction. We know that this is the electro pilic addition. And now essentially what we have to recall from this reaction is that hydrogen gets added to the less substituted carbon because this allows us to form a more stable carbo cion intermediate. So the positive charge would be on the secondary carbon instead of the primary one, the primary carbon is less stable than the secondary one. Right. And then the chloride anion essentially tags the carbo cion to form the final product. Let's go ahead and throw it out. And then we simply want to identify the correct name of the compound. Now, if we consider the name of the compound, we have to enumerate it from right to left because this is where we get a greater number of subscriptions on the right side. Specifically, we would have 22 dimethyl and four chloral arranging alphabetically. The name would be for chloral che to the meal and the parent she is then saying, meaning the correct answer to this problem would be option B Thank you for watching.

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1. A Review of General Chemistry5h 5m
2. Molecular Representations1h 14m
3. Acids and Bases2h 46m
4. Alkanes and Cycloalkanes4h 17m
5. Chirality3h 39m
6. Thermodynamics and Kinetics1h 22m
7. Substitution Reactions1h 48m
8. Elimination Reactions2h 30m
9. Alkenes and Alkynes2h 9m
10. Addition Reactions3h 19m
11. Radical Reactions1h 58m
12. Alcohols, Ethers, Epoxides and Thiols2h 42m
13. Alcohols and Carbonyl Compounds2h 17m
14. Synthetic Techniques1h 26m
15. Analytical Techniques:IR, NMR, Mass Spect7h 3m
16. Conjugated Systems6h 13m
17. Ultraviolet Spectroscopy51m
18. Aromaticity2h 34m
19. Reactions of Aromatics: EAS and Beyond5h 1m
20. Phenols55m
21. Aldehydes and Ketones: Nucleophilic Addition4h 56m
22. Carboxylic Acid Derivatives: NAS2h 51m
23. The Chemistry of Thioesters, Phophate Ester and Phosphate Anhydrides1h 10m
24. Enolate Chemistry: Reactions at the Alpha-Carbon1h 53m
25. Condensation Chemistry2h 9m
26. Amines1h 43m
27. Heterocycles2h 0m
28. Carbohydrates5h 53m
29. Amino Acids4h 20m
30. Peptides and Proteins2h 42m
31. Catalysis in Organic Reactions1h 30m
32. Lipids 2h 50m
33. The Organic Chemistry of Metabolic Pathways2h 52m
34. Nucleic Acids1h 32m
35. Transition Metals6h 14m
36. Synthetic Polymers1h 49m

10. Addition Reactions

Hydrohalogenation

Organic Chemistry

10. Addition Reactions

Hydrohalogenation

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3:06 minutes

Problem 75

Textbook Question

A student was about to turn in the products he had obtained from the reaction of HI with 3,3,3-trifluoropropene when he realized that the labels had fallen off his flasks and he did not know which label belonged to which flask. His friend reminded him of the rule that says the electrophile adds to the sp² carbon bonded to the most hydrogens. In other words, he should label the flask containing the most product 1,1,1-trifluoro-2-iodopropane and label the flask containing the least amount of product 1,1,1-trifluoro-3-iodopropane. Should he follow his friend’s advice?

Verified step by step guidance

Step 1: Understand the reaction mechanism. The reaction of HI with 3,3,3-trifluoropropene is an electrophilic addition reaction. In this reaction, the hydrogen ion (H⁺) acts as the electrophile, and the iodide ion (I⁻) acts as the nucleophile.

Step 2: Apply Markovnikov's rule. Markovnikov's rule states that in the addition of HX (where X is a halogen) to an alkene, the hydrogen atom (H⁺) will add to the sp² carbon atom that is bonded to the greater number of hydrogen atoms. This is because the more stable carbocation intermediate is formed during the reaction.

Step 3: Analyze the structure of 3,3,3-trifluoropropene. The molecule has a double bond between the first and second carbons. The first carbon (C1) is bonded to three fluorine atoms and no hydrogens, while the second carbon (C2) is bonded to two hydrogens. According to Markovnikov's rule, the H⁺ will add to C2, forming a carbocation on C1.

Step 4: Determine the major and minor products. After the carbocation is formed on C1, the iodide ion (I⁻) will attack the positively charged carbon. This results in the formation of 1,1,1-trifluoro-2-iodopropane as the major product. The minor product, 1,1,1-trifluoro-3-iodopropane, would result from the addition of H⁺ to C1 and I⁻ to C2, which is less favorable due to the instability of the carbocation formed on C2.

Step 5: Conclude based on the friend's advice. The friend’s advice is correct. The flask containing the most product should be labeled as 1,1,1-trifluoro-2-iodopropane, and the flask containing the least product should be labeled as 1,1,1-trifluoro-3-iodopropane, as this aligns with Markovnikov's rule and the stability of the intermediates.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Electrophilic Addition

Electrophilic addition is a fundamental reaction mechanism in organic chemistry where an electrophile reacts with a nucleophile, typically involving alkenes or alkynes. In this context, the electrophile (HI) adds to the sp2 carbon of the alkene (3,3,3-trifluoropropene), which is more substituted and has more hydrogen atoms, leading to the formation of more stable carbocation intermediates.

Markovnikov's Rule

Markovnikov's Rule states that in the addition of HX to an alkene, the hydrogen atom from HX will attach to the carbon with the greater number of hydrogen atoms already attached. This rule helps predict the major product of the reaction, guiding the student to label the flask with 1,1,1-trifluoro-2-iodopropane as the major product due to the more favorable formation of a more stable carbocation.

Product Stability and Regioselectivity

Product stability and regioselectivity refer to the preference for the formation of certain products over others based on their stability. In this reaction, the product with the more substituted carbon (1,1,1-trifluoro-2-iodopropane) is favored due to its lower energy and greater stability compared to the less substituted product (1,1,1-trifluoro-3-iodopropane), which aligns with the student's friend's advice.

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