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

Functional Groups

Organic Chemistry

2. Molecular Representations

Functional Groups

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4:27 minutes

Problem 26a,b

Textbook Question

Draw a Lewis structure, and classify each of the following compounds:
(a) CH₃CH₂CONHCH₃
(b) (CH₃CH₂)₂NH

Verified step by step guidance

Step 1: Identify the total number of valence electrons for each compound. For compound (a) CH3CH2CONHCH3, count the valence electrons from each atom: Carbon (C) has 4, Hydrogen (H) has 1, Nitrogen (N) has 5, and Oxygen (O) has 6. For compound (b) (CH3CH2)2NH, count the valence electrons similarly.

Step 2: Draw the skeletal structure of each compound. For compound (a), arrange the atoms in the order given: CH3CH2CONHCH3, with the carbonyl group (C=O) in the middle. For compound (b), arrange the ethyl groups (CH3CH2) around the nitrogen atom.

Step 3: Distribute the valence electrons around the atoms to satisfy the octet rule (or duet for hydrogen). Start by placing electrons to form bonds between atoms, then distribute remaining electrons to complete octets, prioritizing more electronegative atoms like oxygen and nitrogen.

Step 4: Check for formal charges to ensure the most stable Lewis structure. Adjust the placement of electrons if necessary to minimize formal charges, ensuring that the overall charge of the molecule is correct.

Step 5: Classify each compound based on functional groups. For compound (a), identify the amide group (CONH) and classify it as an amide. For compound (b), identify the amine group (NH) and classify it as a secondary amine due to the two ethyl groups attached to the nitrogen.

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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 of a molecule and the lone pairs of electrons that may exist. They are essential for visualizing the arrangement of atoms, the distribution of electrons, and predicting the shape and reactivity of the molecule. In drawing Lewis structures, it is important to account for all valence electrons and ensure that each atom satisfies the octet rule, where applicable.

Functional Groups

Functional groups are specific groups of atoms within molecules that have characteristic properties and reactivity. In organic chemistry, recognizing functional groups such as amides (CONH) and amines (NH) is crucial for classifying compounds and predicting their chemical behavior. For example, in CH3CH2CONHCH3, the CONH segment indicates an amide group, while in (CH3CH2)2NH, the NH group signifies a secondary amine.

Molecular Geometry and Hybridization

Molecular geometry refers to the three-dimensional arrangement of atoms in a molecule, which is influenced by the hybridization of atomic orbitals. Understanding the geometry helps predict the molecule's physical and chemical properties. For instance, the sp3 hybridization in amines leads to a tetrahedral geometry around the nitrogen atom, affecting the molecule's polarity and interactions with other compounds.

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Related Practice

Textbook Question

Draw a Lewis structure, and classify each of the following compounds. The possible classifications are as follows:

alcohol

ether

ketone

aldehyde

carboxylic acid

alkene

(h)

(i)

Textbook Question

Circle the functional groups in the following structures. State to which class (or classes) of compounds the structure belongs.

(g)

(h)

(i)

Textbook Question

Draw a Lewis structure, and classify each of the following compounds:

(e) (CH₃CH₂)₂O

(f) CH₃CH₂CH₂CN

Textbook Question

Draw a Lewis structure, and classify each of the following compounds:

(d) CH₃CHCHCOCl

Textbook Question

Draw a Lewis structure, and classify each of the following compounds. The possible classifications are as follows:

alcohol

ether

ketone

aldehyde

carboxylic acid

alkene

(f)

(g)

Textbook Question

Draw a Lewis structure, and classify each of the following compounds. The possible classifications are as follows: alcohol ether ketone aldehyde carboxylic acid alkene

(d) CH₃CH₂OCHCH₂

(e)

Textbook Question

Classify the following hydrocarbons, and draw a Lewis structure for each one. A compound may fit into more than one of the following classifications:

alkane

alkene

alkyne

cycloalkane

cycloalkene

cycloalkyne

aromatic

hydrocarbon