GC2.Chp15.Ochem.student

GC1 Review Questions

  • Question 1: Indicate the hybridization for the designated atoms.

  • Question 2: Identify the polar covalent compounds from the list:

    • a. TeH2

    • b. BCl3

    • c. NCl3

    • d. CH3CH3

    • e. Si(CH3)2F2

    • f. CO2

  • Question 3: Determine the types of intermolecular forces present between a PCl3 and HCl molecule.

Weakest Electrolytic Solution

  • Question 4: Which solution is the weakest electrolytic solution?

    • a. HCl

    • b. MgCl2

    • c. LiBr

    • d. FeCl3

    • e. K2O

    • f. HF

Acidic Protons

  • Question 5: Identify which of the following does NOT contain acidic protons:

    • a. CH3COOH

    • b. NH3

    • c. HBr

    • d. H3PO4

    • e. HNO3

Bonds in Molecules

  • Question 6: Count the number of sigma (σ) and pi (π) bonds in the molecule:

    • a. 8 σ and 6 π

    • b. 3 σ and 5 π

    • c. 6 σ and 4 π

    • d. 8 σ and 2 π

    • e. 6 σ and 2 π

Chapter 15 Overview

  • Chapter 15 Topics:

    • 15.1 Molecular Structure and Functional Groups

    • 15.2 Organic Molecules and Isomers (Chirality skipped)

    • 15.4 Functional Groups

    • Including Alkanes, Alkenes, and Alkynes

    • Understanding Aromaticity

Rules of Thumb (ROTs) for Organic Compounds

  • Carbon (C): always has 4 bonds

  • Nitrogen (N): typically has 3 bonds (4 indicates a cation, e.g. NH4+)

  • Oxygen (O): typically has 2 bonds

  • Halogens (F, Br, Cl, I): typically have 1 bond

Introduction to Carbon and Organic Chemistry

  • Organic Chemistry: study of carbon compounds, primarily those containing hydrogen.

  • Carbon readily bonds with itself and heteroatoms (common ones: H, N, O, F, P, S, Cl, Br, I).

  • Carbon compounds: Millions exist, with ~15,000 new compounds added daily to the chemical registry.

Unique Characteristics of Organic Molecules

  • Electron Configuration: [He]2s22p2

  • Valence Electrons: 4

  • Tendency to Form Ions: Not favorable (doesn’t form C4+ or C4- ions).

  • Bonding Nature: Forms 4 covalent bonds (σ and π), adhering to the octet rule.

  • Electronegativity (EN): 2.5 (between Li EN = 1.0 and F EN = 4.0).

Hybridization in Carbon Bonds

  • Forms 4 bonds via hybridization.

  • Small size allows for strong, short carbon-carbon bonds, facilitating π-bonding.

Catenation in Carbon

  • Catenation: carbon's ability to bond to itself, results in stable molecular constructs compared to silicon.

    • Atomic sizes:

      • Carbon: 77 pm

      • Silicon: 118 pm

    • Bond strength comparisons: C-C (347 kJ/mol) vs Si-Si (226 kJ/mol)

    • C’s small size leads to better orbital overlap and stability of molecules.

Organic Molecule Complexity

  • Carbon Skeleton: Variation in structures leads to numerous compounds.

    • Structures can be linear, branched, or cyclic.

Bonding Regularity and Hydrogen Attachment

  • Rule of 4 Bonds: Hydrogen count based on carbon's valency.

    • C single-bonded to one atom has 3 H atoms, 2 bonded has 2 H, 3 bonded has 1 H, and 4 bonded means no H.

    • Each C in double bonds treated as if bonded to two other atoms.

Hydrocarbon Examples and Characteristics

  • Hydrocarbons: Compounds of carbon and hydrogen (e.g. methane, ethane, benzene).

  • Bonding Behavior: Rotation in single bonds, fixed in double bonds.

Alkane Family

  • Definition: Alkanes contain only single bonds (saturated hydrocarbons).

  • General Formula: CnH2n+2

  • Alkane Examples: Butane, Pentane, etc.

Naming Alkanes

  • Naming Convention: Root name + prefix + suffix.

    • Example Roots: meth- (1), eth- (2), prop- (3), but- (4), pent- (5).

Cycloalkanes

  • Structure: CnH2n; rings insensitive to saturation.

  • Stability: 5 & 6 member rings are more stable than 3 or 4.

Structural and Geometric Isomers

  • Isomer Types: Same molecular formula but different arrangements.

  • Properties: Depend on specific structural orientations and functional groups.

Alkenes and Alkynes Overview

  • Alkenes: Include double bonds (general formula CnH2n).

  • Alkynes: Include triple bonds (general formula CnH2n-2).

Common Functional Groups

  • Functional Groups: Specific atomic combinations that influence chemical reactivity and properties.

Alcohols, Haloalkanes, and Amines

  • Alcohols: Contain -OH; named with suffix -ol.

  • Haloalkanes: Contain halogen bonded to carbon.

  • Amines: Derivatives of ammonia (NH3) with weak base characteristics.

Carbonyl Group and Its Families

  • Carbonyl Group: Found in aldehydes, ketones, carboxylic acids, and other functional groups; highly polar.

  • Example Compounds: Methanal and Ethanal with diverse chemical uses.

Summary of Functional Groups

  • Various examples, descriptions, and their chemical behavior in relation to other molecules.