Table of contents

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

4. Alkanes and Cycloalkanes

IUPAC Naming

Organic Chemistry

4. Alkanes and Cycloalkanes

IUPAC Naming

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5:15 minutes

Problem 9

Textbook Question

Without looking at the structures, give molecular formulas for the compounds: (a) 4-(1,1-dimethylethyl)octane and (b) 5-(1,2,2-trimethylpropyl)nonane. Use the names of the groups to determine the number of carbon atoms; then use the (2n + 2) rule.

Verified step by step guidance

Step 1: Begin by identifying the main chain in each compound. For compound (a), the main chain is octane, which has 8 carbon atoms. For compound (b), the main chain is nonane, which has 9 carbon atoms.

Step 2: Identify the substituents attached to the main chain. In compound (a), the substituent is 4-(1,1-dimethylethyl), which consists of a tert-butyl group. This group has 4 carbon atoms. In compound (b), the substituent is 5-(1,2,2-trimethylpropyl), which consists of a group with 6 carbon atoms.

Step 3: Add the number of carbon atoms from the main chain and the substituents. For compound (a), add 8 (from octane) and 4 (from the tert-butyl group) to get the total number of carbon atoms. For compound (b), add 9 (from nonane) and 6 (from the trimethylpropyl group) to get the total number of carbon atoms.

Step 4: Use the general formula for alkanes, C_nH_2n+2, to determine the number of hydrogen atoms. For compound (a), substitute the total number of carbon atoms into the formula to find the number of hydrogen atoms. Repeat the process for compound (b).

Step 5: Combine the number of carbon and hydrogen atoms to write the molecular formula for each compound. Ensure that the formula reflects the total number of each type of atom present in the compound.

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Key Concepts

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

IUPAC Nomenclature

IUPAC nomenclature is a systematic method of naming organic chemical compounds as recommended by the International Union of Pure and Applied Chemistry (IUPAC). It provides a standardized way to describe the structure of a compound using specific rules, which include identifying the longest carbon chain, numbering the chain, and naming substituents.

Alkyl Groups

Alkyl groups are groups of carbon and hydrogen atoms arranged in a chain, derived from alkanes by removing one hydrogen atom. They are named based on the number of carbon atoms they contain, such as methyl (CH3), ethyl (C2H5), and propyl (C3H7). Understanding alkyl groups is crucial for determining the structure and molecular formula of complex organic compounds.

Molecular Formula Calculation

The molecular formula of an alkane can be determined using the general formula CnH2n+2, where n is the number of carbon atoms. This formula accounts for the saturated nature of alkanes, which have single bonds between carbon atoms. By identifying the number of carbon atoms in the main chain and substituents, one can calculate the total number of hydrogen atoms to derive the molecular formula.