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.