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

Formal Charges

Organic Chemistry

1. A Review of General Chemistry

Formal Charges

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3:24 minutes

Problem 17d

Textbook Question

Draw the Lewis structure for each of the following:
d. ⁺C2H5

Verified step by step guidance

Step 1: Determine the total number of valence electrons in the molecule. Carbon (C) has 4 valence electrons, hydrogen (H) has 1 valence electron, and the positive charge (+) indicates the loss of one electron. For C2H5+, calculate the total valence electrons as follows: \( (2 \times 4) + (5 \times 1) - 1 \).

Step 2: Arrange the atoms in the molecule. Carbon is less electronegative than hydrogen, so the two carbons will form the backbone of the structure. Attach the hydrogens to the carbons, ensuring that the structure reflects the molecular formula \( C_2H_5^+ \).

Step 3: Form a single bond between the two carbon atoms. Then, attach the hydrogens to the carbons using single bonds. Distribute the hydrogens such that one carbon has three hydrogens (\( CH_3 \)) and the other carbon has two hydrogens (\( CH_2 \)).

Step 4: Adjust the structure to account for the positive charge. Since the molecule is a cation, one of the carbons will have an incomplete octet. Remove one electron from the carbon atom that is bonded to fewer hydrogens (the \( CH_2 \) group), resulting in a carbocation.

Step 5: Verify the structure by checking that the total number of valence electrons matches the calculated total from Step 1 and that the positive charge is correctly represented. Ensure that all hydrogens have a single bond and that the carbocation is clearly indicated.

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Key Concepts

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

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 use dots to represent electrons and lines to represent bonds between atoms. Understanding how to draw Lewis structures is essential for visualizing molecular geometry and predicting reactivity.

Valence Electrons

Valence electrons are the outermost electrons of an atom and are crucial in determining how atoms bond with each other. The number of valence electrons influences the atom's ability to form bonds, either by sharing electrons (covalent bonds) or transferring them (ionic bonds). Knowing the valence electron count for each atom helps in accurately constructing Lewis structures.

Formal Charge

Formal charge is a concept used to determine the charge distribution within a molecule, calculated based on the number of valence electrons, the number of bonds, and the number of lone pair electrons on an atom. It helps in assessing the stability of a Lewis structure; structures with formal charges closest to zero are generally more stable. Understanding formal charge is vital for evaluating different resonance structures and their contributions to the overall molecule.