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

2. Molecular Representations

How To Determine Solubility

Organic Chemistry

2. Molecular Representations

How To Determine Solubility

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2:37 minutes

Problem 9a

Textbook Question

Classify the following molecules as hydrophilic, hydrophobic, lipophilic, or lipophobic. Each molecule should have two classifications.
(a)

Verified step by step guidance

Step 1: Understand the definitions of the terms hydrophilic, hydrophobic, lipophilic, and lipophobic. Hydrophilic refers to molecules that interact well with water (water-loving), while hydrophobic refers to molecules that repel water (water-fearing). Lipophilic refers to molecules that dissolve well in lipids or fats (fat-loving), and lipophobic refers to molecules that repel lipids or fats (fat-fearing).

Step 2: Analyze the structure of the given molecule. Look for functional groups or structural features that indicate polarity or non-polarity. Polar molecules (e.g., those with hydroxyl (-OH), carboxyl (-COOH), or amino (-NH2) groups) are typically hydrophilic and lipophobic, while non-polar molecules (e.g., hydrocarbons or molecules with long alkyl chains) are typically hydrophobic and lipophilic.

Step 3: Determine the molecule's solubility in water. If the molecule has polar functional groups, it is likely hydrophilic. If it lacks polar groups and consists mostly of non-polar bonds, it is likely hydrophobic.

Step 4: Assess the molecule's solubility in lipids or fats. Non-polar molecules tend to dissolve well in lipids, making them lipophilic. Polar molecules, on the other hand, are generally lipophobic.

Step 5: Assign two classifications to the molecule based on its structural features and solubility properties. For example, a molecule with both polar and non-polar regions may exhibit dual characteristics, such as being hydrophilic and lipophilic.

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Key Concepts

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

Hydrophilicity and Hydrophobicity

Hydrophilicity refers to the affinity of a molecule for water, often due to the presence of polar functional groups that can form hydrogen bonds with water. Conversely, hydrophobicity describes molecules that repel water, typically nonpolar substances that do not interact favorably with water molecules. Understanding these properties is crucial for predicting how molecules behave in aqueous environments.

Lipophilicity and Lipophobicity

Lipophilicity indicates a molecule's affinity for lipids or fats, often associated with nonpolar characteristics that allow for solubility in organic solvents. In contrast, lipophobicity describes molecules that do not interact well with lipids, usually due to polar or charged functional groups. These classifications are essential for understanding the behavior of molecules in biological membranes and their interactions with lipids.

Functional Groups and Molecular Polarity

Functional groups are specific groups of atoms within molecules that determine their chemical reactivity and properties, including polarity. The polarity of a molecule is influenced by the presence of electronegative atoms (like oxygen or nitrogen) and the overall molecular structure. Recognizing functional groups helps in classifying molecules as hydrophilic or hydrophobic, and lipophilic or lipophobic, based on their interactions with water and lipids.