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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3:22 minutes

Problem 49a

Textbook Question

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

Verified step by step guidance

Step 1: Identify the molecular structure provided in the problem. Look at each atom in the molecule and determine its valence electron count based on its position in the periodic table.

Step 2: Recall that lone pairs are unshared electrons on an atom. For each atom, calculate the number of lone pairs by subtracting the number of bonds and formal charges from the total valence electrons.

Step 3: Add lone pairs to atoms that need them to satisfy the octet rule (or duet rule for hydrogen). Ensure that the total number of electrons around each atom matches its expected valence configuration.

Step 4: Double-check the formal charges on each atom after adding lone pairs. Use the formula: Formal Charge = Valence Electrons - (Lone Pair Electrons + 1/2 Bonding Electrons). Adjust lone pairs if necessary to minimize formal charges.

Step 5: Verify the overall structure for stability and resonance possibilities. Ensure that the molecule adheres to fundamental rules of organic chemistry, such as the octet rule and proper electron distribution.

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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. They play a crucial role in determining the geometry and reactivity of molecules. Understanding how to identify and represent lone pairs is essential for accurately drawing Lewis structures and predicting molecular shapes.

Lewis Structures

Lewis structures are diagrams that represent the bonding between atoms in a molecule and the lone pairs of electrons. They provide a visual way to understand the arrangement of electrons and the connectivity of atoms. Drawing Lewis structures correctly requires knowledge of valence electrons and the octet rule, which states that atoms tend to form bonds until they are surrounded by eight valence electrons.

Octet Rule

The octet rule is a chemical rule of thumb that states atoms tend to bond in such a way that they each have eight electrons in their valence shell, achieving a stable electron configuration similar to that of noble gases. This rule helps predict how atoms will bond and the arrangement of electrons in molecules. However, there are exceptions to this rule, particularly for elements in the third period and beyond.

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