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

1. A Review of General Chemistry

Bonding Preferences

Organic Chemistry

1. A Review of General Chemistry

Bonding Preferences

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4:21 minutes

Problem 49c

Textbook Question

Draw in all missing lone pairs for the following molecules.
(c)

Verified step by step guidance

Step 1: Identify the molecule shown in the image. The structure represents a ketone functional group, specifically 2-propanone (acetone). The central carbon is double-bonded to an oxygen atom and single-bonded to two methyl groups.

Step 2: Recall that oxygen typically has six valence electrons. In this structure, two of these electrons are involved in the double bond with carbon, leaving four electrons to form lone pairs.

Step 3: Add two lone pairs to the oxygen atom. These lone pairs should be placed symmetrically around the oxygen atom to reflect its tetrahedral electron geometry.

Step 4: Verify that the central carbon atom has a complete octet. The carbon is bonded to two methyl groups and the oxygen atom via a double bond, satisfying the octet rule.

Step 5: Confirm that all other atoms in the molecule (hydrogens and carbons) have the correct number of bonds and no lone pairs are needed for them. Hydrogen atoms are always single-bonded, and the methyl groups are fully saturated.

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Key Concepts

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

Lone Pairs

Lone pairs are pairs of valence electrons that are not involved in bonding and are localized on a single atom. In organic chemistry, recognizing lone pairs is crucial for understanding molecular geometry, reactivity, and the overall electronic structure of molecules. They can influence the polarity and hydrogen bonding capabilities of a compound.

Lewis Structures

Lewis structures are diagrams that represent the bonding between atoms in a molecule and the lone pairs of electrons that may exist. They provide a visual representation of the arrangement of electrons, helping to predict molecular shape and reactivity. Drawing Lewis structures accurately is essential for identifying missing lone pairs in a given molecule.

Valence Shell Electron Pair Repulsion (VSEPR) Theory

VSEPR theory is a model used to predict the geometry of individual molecules based on the repulsion between electron pairs in the valence shell of the central atom. According to this theory, electron pairs, including lone pairs, will arrange themselves to minimize repulsion, which is key to understanding the three-dimensional shape of molecules and the placement of lone pairs.

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