C1-INTRO TO ORG CHEM

Chapter 1: Introduction to Organic Chemistry

Learning Objectives

  • Differentiate between Organic and Inorganic compounds

  • Identify types of Carbon

  • Classify the organic compound

  • Identify functional groups and alkyl groups with structural formulas

  • Identify homologous series

  • Different ways of writing structural formulas

  • Explain isomerism

  • Identify the names of organic compounds

  • Explain types of reactions

  • Explain physical properties

Introduction to Organic Chemistry

  • Definition: Organic compounds are primarily those based on carbon; historically, they were considered to be from living sources.

  • Current understanding: Includes biological molecules, drugs, solvents, and dyes; excludes metal salts and large polymers without sequences.

  • Career paths: forensic scientists, pharmacists, medical doctors, biotechnologists, and homeopathy practitioners.

Organic Compounds

Types of Formula

  • Structural formulas: Expanded, condensed, line drawing, Fischer projection.

  • Isomerism Types:

    • Structural isomerism: Variations in carbon skeleton or functional group positions.

    • Stereoisomerism: Variations in geometry (cis/trans) and optical isomers (enantiomers).

Functional Groups

  • Definition: Groups of atoms within molecules that determine the characteristics and reactions.

  • Types of functional groups include alkenes, alkynes, aromatics, alcohols, ethers, aldehydes, ketones, and carboxylic acids.

Properties of Organic and Inorganic Compounds

Comparison Table (Table 11.1)

Property

Organic Example (C3H8)

Inorganic Example (NaCl)

Elements Present

C and H

Mostly metals and nonmetals

Particles

Molecules

Ions

Bonding

Mostly covalent

Mostly ionic

Polarity of Bonds

Nonpolar, unless polar covalent

Most ionic

Melting Point

Usually low

Usually high

Boiling Point

Usually low

Usually high

Flammability

High

Low

Solubility in Water

Not soluble (unless polar)

Mostly soluble

The Bonding of Carbon

  • Carbon is central to organic chemistry.

  • Can form single, double, and triple bonds.

  • Types of carbon based on hybridization and bonding structures.

Homologous Series

  • Definition: A series of compounds with the same functional groups and similar chemical properties, differing by a –CH2– group.

    • Example: Alkanes, where the general formula is CnH2n+2.

Types of Functional Groups

Multiple Carbon-Carbon Bonds

  • Alkenes: C=C (double bonds)

  • Alkynes: C≡C (triple bonds)

  • Arenes: Aromatic rings.

  • Common Functional Groups include organic halides, alcohols, ethers, aldehydes, ketones, carboxylic acids, esters, amines, amides.

Structural Formula

  • Shows the number of atoms and their bonding arrangements.

  • Four Ways to Write Structural Formula:

    1. Lewis / Expanded structural formula

    2. Condensed structural formula

    3. Line drawing / Skeletal formula

    4. Fischer Projection

Isomerism

Structural Isomerism

  • Different carbon skeletons or functional group arrangements.

Stereoisomerism

  • Includes geometric (cis/trans) and optical isomers.

  • Chiral centers: Asymmetric carbon atoms that lead to enantiomers, which are non-superimposable mirror images.

Naming Organic Compounds

IUPAC Naming Rules

  1. Identify the functional group (suffix).

  2. Identify the parent compound (longest carbon chain).

  3. Identify any substituents (prefix).

  4. List substituents in alphabetical order.

  5. Indicate repetition of substituents with prefixes (di-, tri-, etc.).

Reactions of Organic Compounds

Types of Reactions

  1. Addition Reactions: Formation of new products by adding reactants to unsaturated compounds.

  2. Substitution Reactions: Replacing one atom/group with another in a reactant.

  3. Elimination Reactions: Removing small molecules to create double/triple bonds.

  4. Rearrangement Reactions: Internal rearrangement of atoms to form a new structure.

Physical Properties of Organic Compounds

Boiling Point

  • Influences of intermolecular forces, surface area, and molecular shape.

Solubility in Water

  • Hydrophilic vs Hydrophobic interactions determine solubility based on polarity.

Acids and Bases

General Properties of Acids

  • Sour taste, ability to neutralize bases, changes litmus paper from blue to red.

General Properties of Bases

  • Bitter taste, slippery feel, ability to neutralize acids, changes litmus paper from red to blue.

Acid-Base Theories

Arrhenius Theory

  • Acids: Produce H+ in solution.

  • Bases: Produce OH− in solution.

Brønsted-Lowry Theory

  • Acids: H+ donors.

  • Bases: H+ acceptors.

Lewis Theory

  • Acids: Electron pair acceptors.

  • Bases: Electron pair donors.

Conclusion

  • Understanding organic chemistry involves studying its compounds, properties, reactions, and the fundamental principles underlying their behavior in both theoretical and practical applications.