If cyclopentane reacts with more than one equivalent of Cl 2 at a high temperature, how many dichlorocyclopentanes would you expect to obtain as products?

All right. Hello everyone. So this question is asking us if more than one equivalent of co two reacts with cyclohexane. How many di chloral hexane are produced at high temperatures? Option? A says seven B says 10 C says 13 and D says 18. So here the starting material that we're looking at is cyclohexane, which is just a six member ring, right? No double bonds inside of the ring. Now, at high temperatures, the reaction of more than one equivalent of elemental chlorine with cyclohexane produces dilor oyo hexane. So basically two hydrogens from Cyclohexane are replaced with two atoms of chlorine. Now, the way that this happens is sequential, right? Both chorines aren't going to be added at the same time. The first step is mono chlorination in which only one hydrogen is replaced with chlorine leading to the addition of only one chlorine on to cyclohexane. Now, because cyclohexane is symmetrical, all of its hydrogens are going to be equivalent. And so what that means is that if you mono chlorinate any of the given positions here, if you mono chlorinate any of the given hydrogens in cyclohexane, the product will be the exact same, the second step, however, is our di chlorination in which now our second hydrogen is replaced with chlorine and this is where we see some variability, right? This is what the question is referring to because when you go through the second chlorination, chloral cyclohexane is still symmetrical. That's true. But it now has different sets of unique hydrogens, right? The first unique set is on the carbon attached to chlorine directly. The second set is one position away from the carbon that has chlorine. And then our 3rd and 4th positions are the remaining carbons inside of the ring. So now we have to count the total number of products obtained after undergoing the second chlorination, add each a different set of hydrogens. Now, in addition to the counts that we're going to make, it's important to recognize that stereo isomers are a thing to consider, right? Because when chlorine is added to our cyclohexane, here, we're going to end up with two chiral carbons. This means that chlorine is either depicted on a wedge or a dash. So we have to account for all possibilities. In any case, though, let's say we go ahead and di chlorinate carbon number one, this would create a total of one product, right? Because there's only one hydrogen on position one that creates one product after di chlorination. But now let's consider set two. Now, taking into account the combination of chlorine being depicted as either a wedge or a dash, we end up with a total of four different stereo isomers, technically, right, the difference however, is that two of them are actually identical because they're meso compounds. So the total number of unique products you get is actually three. Even though when you account for chlorine being depicted on either a wedge or a dash on both carbons, you get four different possibilities, but really two are identical. So now moving on to the third set, you're also going to end up with three new products. If you add the second chlorine onto carbon number three, and this is true for the same reasons described before, right? Tech, technically, you have four different possibilities, but really two of them are identical to each other. And last but not least adding the second chlorine atom to carbon number four would once again give you three products for the same reasons described four carbons, two and three. And so when you add the total number of unique products, your total adds up to 10, which means that option B as in boy is our correct answer and there you have it. So with that being said, thank you so very much for watching. And I hope you found this helpful.

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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

11. Radical Reactions

Free Radical Halogenation

Organic Chemistry

11. Radical Reactions

Free Radical Halogenation

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Problem 5

Textbook Question

If cyclopentane reacts with more than one equivalent of Cl₂ at a high temperature, how many dichlorocyclopentanes would you expect to obtain as products?

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Analyze the structure of cyclopentane: Cyclopentane is a cyclic alkane with the molecular formula C5H10. It consists of a five-membered ring where all carbon atoms are sp3 hybridized, and all hydrogens are equivalent due to the symmetry of the molecule.

Understand the reaction conditions: The reaction involves Cl2 and high temperature, which suggests a free radical halogenation mechanism. In this mechanism, chlorine radicals will abstract hydrogens from the cyclopentane ring, leading to the formation of chlorinated products.

Determine the possible positions for chlorination: Since all hydrogens in cyclopentane are equivalent, the first chlorination will produce only one monochlorocyclopentane product. For the second chlorination, the chlorine can attach to any of the remaining hydrogens, leading to different dichlorocyclopentane isomers.

Consider the symmetry of the molecule: Due to the symmetry of cyclopentane, some dichlorocyclopentane products will be identical. For example, if the two chlorines are attached to adjacent carbons, the product will be the same regardless of which adjacent carbons are chosen. Similarly, if the chlorines are attached to carbons that are not adjacent, the symmetry of the ring will reduce the number of unique products.

Count the unique dichlorocyclopentane isomers: Based on the positions of the chlorines (e.g., on the same carbon, on adjacent carbons, or on carbons separated by one or more carbons), determine the total number of unique dichlorocyclopentane products. This requires considering both the relative positions of the chlorines and the symmetry of the molecule.

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Key Concepts

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

Free Radical Halogenation

Free radical halogenation is a reaction mechanism where alkanes react with halogens (like Cl<sub>2</sub>) under heat or light to form alkyl halides. This process involves the formation of free radicals, which are highly reactive species that can lead to multiple substitution reactions. Understanding this mechanism is crucial for predicting the products formed when cyclopentane reacts with chlorine.

Substitution Patterns

In the context of cyclopentane, substitution patterns refer to the different positions on the cyclopentane ring where chlorine atoms can be added. Due to the symmetrical nature of cyclopentane, multiple isomers can form depending on whether the chlorine atoms are added to the same carbon or different carbons. Recognizing these patterns helps in determining the number of distinct dichlorocyclopentane products.

Isomerism

Isomerism is the phenomenon where compounds with the same molecular formula can have different structural arrangements. In the case of dichlorocyclopentanes, the presence of two chlorine atoms can lead to various isomers, including positional isomers and stereoisomers. Understanding isomerism is essential for accurately predicting and counting the different products formed in the reaction.

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If cyclopentane reacts with more than one equivalent of Cl2 at a high temperature, how many dichlorocyclopentanes would you expect to obtain as products?

Key Concepts

Free Radical Halogenation

Substitution Patterns

Isomerism

Watch next

If cyclopentane reacts with more than one equivalent of Cl₂ at a high temperature, how many dichlorocyclopentanes would you expect to obtain as products?