10.1 FUNDAMENTALS OF ORGANIC CHEM

Page 1: Introduction

• Topic: Organic Chemistry 10.1 Fundamentals

• Author: Merinda Sautel, Alameda Int’l Jr/Sr High School, Lakewood, CO

• Contact: msautel@jeffco.k12.co.us

Page 2: Essential Idea

• Organic chemistry focuses on the chemistry of compounds containing carbon.

• Nature of Science (1.4): Importance of serendipity in scientific discoveries (e.g., PTFE and super glue).

• Nature of Science (4.5): Ethical implications of chemicals like drugs, additives, and pesticides that can harm people and the environment.

Page 3: International-Mindedness

• A small number of nations control the world’s oil resources, influencing global politics.

• Importance of interdependence between oil-importing and exporting countries.

• Octane rating measures fuel performance, highly variable by region due to different measurement practices.

Page 4: Theory of Knowledge

• The term "organic chemistry" stems from historic misconceptions about a vital force needed to explain life chemistry.

• Discussion on how vocabulary can develop from misunderstandings.

• Example: Kekule's dream-led inspiration for the cyclic structure of benzene; questioning the role of non-analytical knowledge in scientific discovery.

Page 5: Understanding/Key Idea 10.1.A

• A homologous series is a series of compounds in the same family with the same general formula, differing by a common structural unit.

Page 6: Homologous Series

• Definition: A family of organic compounds sharing common features.

• Successive members differ by a –CH2 group.

• Represented by the same general formula.

• Show a gradation in physical properties and similar chemical properties.

Page 7: Members Differ by –CH2

• Moving from one member of a homologous series to the next increases molecular mass by a fixed amount (addition of –CH2).

• Example: Transition from propane to butane adds one carbon and two hydrogen atoms.

Page 8: Members Represented by Same General Formula

• Alkanes: CnH2n+2; Alkenes: CnH2n.

• Functional Group: A small atom group that gives characteristic properties to compounds (e.g., Alcohols: CnH2n+1OH or ROH).

Page 9: Members Show Gradation of Physical Properties

• Physical properties (boiling point, density, viscosity) vary predictably as the chain length changes due to the addition of –CH2 groups.

Page 10: Members Show Similar Chemical Properties

• Same functional groups imply similar reactivity; predicting properties based on characteristic reactions of functional groups is possible.

Page 11: Application/Skills

• Be prepared to explain boiling point trends within homologous series.

Page 12: Boiling Point Trends

• Boiling point increases with longer carbon chains due to stronger van der Waals forces.

Page 13: Boiling Points of Alkanes

• First four alkanes: gas at room temperature.

• Next four: liquid.

• Notable boiling points: Methane (-164°C) to Octane (125°C).

Page 14: Application/Skills

• Distinguish between empirical, molecular, and structural formulas.

Page 15: Empirical Formula

• Definition: Simplest whole number ratio of atoms in a compound.

• Derived from combustion analysis but does not provide actual atom counts.

Page 16: Molecular Formula

• Definition: Actual number of each element's atoms, a multiple of the empirical formula.

• Does not indicate the arrangement of atoms; thus, limited in value.

Page 17: Understanding/Key Idea 10.1.B

• Structural formulas can be presented in full and condensed formats.

Page 18: Structural Formula

• Full structural formulas must depict every bond and atom.

• Must show all C's, H's, and functional groups for full credit. Skeletal structures are rejected.

Page 19: Condensed Structural Formula

• Simplified structural formula that omits assumed bonds and groups atoms.

Page 20: Stereochemical Formula

• Attempts to depict three-dimensional atomic positions.

• Uses solid wedge for bonds in front of the page and dotted line for those at the back.

Page 21: Understanding/Key Idea 10.1.C

• Saturated Compounds: Contain only single bonds.

• Unsaturated Compounds: Contain double or triple bonds.

Page 22: Guidance

• Apply IUPAC rules for naming:

  1. Non-cyclic alkanes and halogenoalkanes (up to halohexanes).

  2. Alkenes (up to hexene).

  3. Alkynes (up to hexyne).

Page 23: Guidance

• Compounds with up to 6 carbon atoms with one functional group: alcohols, ethers, aldehydes, halogenoalkanes, ketones, esters, carboxylic acids, amines, amides, nitriles, arenes.

Page 24: Nomenclature: IUPAC System

• IUPAC provides a systematic naming process based on molecule size and functional groups.

Page 25: Rule 1: Identify Longest Straight Chain

• Longest carbon chain is the “stem.” Memorize:

  • Meth: 1, Eth: 2, Prop: 3, But: 4, Pent: 5, Hex: 6, Hept: 7, Oct: 8, Non: 9, Dec: 10.

Page 26: Rule 2: Identify Functional Group

• Functional groups impart specific suffixes, replacing –ane in parent alkanes.

Page 27: Understanding/Key Idea 10.1.D

• Functional groups are the reactive parts of molecules.

Page 28: Guidance

• Differentiate between class names and functional group names (e.g., -OH: functional group hydroxyl; class name alcohol).

Page 29: Functional Group: C-C (Alkanes)

• Alkanes:

  • Suffix: –ane (saturated hydrocarbons).

  • General formula: CnH2n+2.

  • Class: alkane; Functional group: none.

Page 30: Functional Group: C=C (Alkenes)

• Alkenes:

  • Suffix: –ene (unsaturated).

  • Named by the smallest numbered carbon in the double bond (e.g., but-1-ene).

  • General formula: CnH2n.

Page 31: Functional Group: C≡C (Alkynes)

• Alkynes:

  • Suffix: –yne (unsaturated).

  • Named by the smallest numbered carbon in the triple bond (e.g., but-1-yne).

  • General formula: CnH2n-2.

Page 32: Functional Group: -OH (Alcohols)

• Alcohols:

  • Suffix: –anol.

  • Named with position of functional group (e.g., propan-2-ol).

  • General formula: CnH2n+1OH.

Page 33: Functional Group: R-O-R’ (Ethers)

• Ethers:

  • Suffix: –oxyalkane.

  • General formula: R-O-R’.

Page 34: Functional Group: -C=O (Aldehydes)

• Aldehydes:

  • Suffix: –anal.

  • Named with carbon counting (e.g., propanal).

  • General formula: R-CHO.

Page 35: Functional Group: R-C=O-R’ (Ketones)

• Ketones:

  • Suffix: –anone.

  • General formula: R-CO-R’.

Page 36: Functional Group: -C=O, O-H (Carboxylic Acids)

• Carboxylic Acids:

  • Suffix: –anoic acid.

  • General formula: CnH2n+1COOH.

Page 37: Functional Group: -C=O, O-R (Esters)

• Esters:

  • Suffix: –anoate.

  • General formula: R-COO-R’.

Page 38: Functional Group: -NH2 (Amines)

• Amines:

  • Suffix: –anamine.

Page 39: Primary, Secondary, Tertiary Amines

• Primary: One –NH2 group.

• Secondary: One alkyl group bonded to nitrogen.

  • Example: N-methylpropanamine.

• Tertiary: Two alkyl groups bonded to nitrogen.

Page 40: Functional Group: -C=O, N-H (Amides)

• Amides:

  • Suffix: –anamide.

Page 41: Primary, Secondary, Tertiary Amides

• Primary: One –NH2 group.

• Secondary: One alkyl group bonded to nitrogen.

• Tertiary: Two alkyl groups bonded to nitrogen.

Page 42: Functional Group: C≡N (Nitriles)

• Nitriles:

  • Suffix: –anenitrile.

Page 43: Functional Group: Arenes (Aromatic Compounds)

• Arenes contain the benzene ring.

Page 44: Understanding/Key Idea 10.1.E

• Benzene is an aromatic, unsaturated hydrocarbon.

Page 45: Application/Skills

• Discuss the structure of benzene using physical and chemical evidence.

Page 46: Structure of Benzene

• Benzene has alternating double bonds between three pairs of carbon atoms.

Page 47: Historical Model of Benzene

• Kekule's model (1865) proposed cyclic arrangement; explained some properties but not low reactivity.

Page 48: Advances in Benzene Structure

• Current model developed with advanced technology; formula C6H6.

Page 49: Structure Geometry of Benzene

• Each carbon in benzene is sp2 hybridized, forming sigma bonds at 120° angles.

Page 50: Benzene's Delocalized Pi Electron Cloud

• P orbitals on carbon overlap, creating a stable, delocalized pi electron cloud.

Page 51: Bonding in Benzene

• All carbon bonds are equal.

Page 52: Stability of Benzene Structure

• More stable than Kekule structure by about 152 kJ/mol.

Page 53: Rule 3: Identify Substituent Groups

• Substituents are named as prefixes or suffixes based on their number and type.

Page 54: Naming Multiple Substituents

• Prefixes like di-, tri-, etc., are utilized when multiple identical substituents are present.

Page 55: Understanding/Key Idea 10.1.F

• Structural Isomers: Same molecular formula but different atom arrangements.

Page 56: Traits of Structural Isomers

• Unique chemical/physical properties; count of isomers increases with molecular complexity.

Page 57: Application/Skills

• Use IUPAC rules to name straight-chain and branched isomers.

Page 58: Isomer Count Examples

• Butane (C4H10): 2 isomers.

• Pentane (C5H12): 3 isomers.

• Hexane (C6H14): 5 isomers.

Page 59: Isomer Drawing Practice

• Draw and name isomers for butane, pentane, and hexane.

Page 60: Isomers of Alkenes and Alkynes

• Butene, pentene, and hexene has multiple isomer options.

Page 61: Isomer Drawing Practice for Alkenes

• Practice drawing and naming isomers for butene, pentene, and hexene.

Page 62: Isomers of Alkynes

• Butyne, pentyne, and hexyne also have multiple isomer options.

Page 63: Isomer Drawing Practice for Alkynes

• Practice drawing and naming isomers for butyne, pentyne, and hexyne.

Page 64: Application/Skills

• Identify primary, secondary, and tertiary carbon atoms in various compounds.

Page 65: Classes of Compounds

• Definitions for primary, secondary, and tertiary carbon atoms and their characteristics.

Page 66: Examples of Carbon Classifications

• Identifying primary, secondary, and tertiary alcohols with examples.

Page 67: Trends in Physical Properties

• Discuss volatility and solubility of compounds with various functional groups.

Page 68: Influence of Structure on Properties

• Both hydrocarbon skeleton and functional group impact physical properties.

Page 69: Volatility

• Measure of how easily substances vaporize; related to intermolecular forces.

Page 70: Factors Affecting Volatility

• Length of carbon chains and branching influence boiling points and volatility.

Page 71: Comparison of Volatility

• Comparing ethanol and propane highlights the effects of hydrogen bonding on volatility.

Page 72: Summary of Volatility

• Ranking of various compounds based on volatility and boiling point trends.

Page 73: Solubility in Water

• Solubility is linked to ability to form hydrogen bonds with water.

Page 74: Hydrocarbon Influence

• Non-polar hydrocarbon skeleton reduces solubility in water.

Page 75: Functional Group Influence on Solubility

• Alcohols, carboxylic acids, and amines: soluble; others less so.

Page 76: Citations

• References to textbooks and resources that contribute to the presentation material.

Key Ideas Summary of Organic Chemistry 10.1 Fundamentals

Essential Idea

• Focuses on compounds containing carbon.

• Importance of serendipity in scientific discoveries and ethical implications of chemicals affecting health and the environment.

International-Mindedness

• Oil resource control by a few nations influences global politics; interdependence exists between oil-importing and exporting countries.

Theory of Knowledge

• Organic chemistry term originates from misconceptions; vocabulary evolves from misunderstandings.

Understanding/Key Idea 10.1.A

• Homologous series: compounds in the same family with the same general formula, differing by a common structural unit.

Understanding/Key Idea 10.1.B

• Structural formulas can be presented in full and condensed formats, with clear differentiation required for functional groups.

Understanding/Key Idea 10.1.C

• Distinction between saturated (only single bonds) and unsaturated compounds (double or triple bonds).

Understanding/Key Idea 10.1.D

• Functional groups are the reactive parts of molecules; understanding their classification is essential.

Understanding/Key Idea 10.1.E

• Benzene is an aromatic hydrocarbon with a stable structure different from historical models.

Understanding/Key Idea 10.1.F

• Structural isomers share the same molecular formula but differ in atom arrangements, leading to unique chemical and physical properties.