Chapter 10: Chemical Bonding

Bond Classification and Electronegativity

Chemical bonds are classified based on the difference in electronegativity (EN) between the atoms involved. Electronegativity is a measure of an atom's ability to attract shared electrons in a chemical bond.

• Pure Covalent Bond: Occurs when the EN difference is 0 (e.g., F-F bond).

• Polar Covalent Bond: Occurs when the EN difference is between 0.4 and 2.0 (e.g., N-H bond, EN difference = 0.9).

• Ionic Bond: Occurs when the EN difference is greater than 2.0.

• Example: The bond between nitrogen (EN = 3.0) and hydrogen (EN = 2.1) is polar covalent because 3.0 - 2.1 = 0.9.

Electron and Molecular Geometry

The geometry of molecules is determined by the number of bonding pairs and lone pairs around the central atom.

• Trigonal Planar: 3 single bonds, no lone pairs (e.g., BF3).

• Linear: 2 double bonds, no lone pairs (e.g., CO2).

Lewis Dot Structures

Lewis dot structures represent the valence electrons of atoms. The number of valence electrons corresponds to the group number in the periodic table.

• Example: Sodium (Na) has 1 valence electron; Oxygen (O) has 6 valence electrons.

Chapter 11: Gases

Kinetic Molecular Theory of Gases

The kinetic molecular theory explains the behavior of gases:

• Gases consist of particles in constant, random motion.

• There are no attractive or repulsive forces between particles.

• The volume of gas particles is negligible compared to the space between them.

• The speed of particles increases with temperature.

Gas Law Calculations

• Pressure Conversion: 1 atm = 760 mmHg. To convert atm to mmHg, multiply by 760.

• Boyle's Law:

• Charles's Law:

• Ideal Gas Law:

• Example: To find moles of Cl2 at given P, V, and T, use .

Chapter 13: Solutions

Definitions: Solution, Solute, Solvent

A solution is a homogeneous mixture of two or more substances. The solute is the minority component, and the solvent is the majority component.

Solubility and Intermolecular Attractions

• Solvent-solute attractions must overcome solute-solute and solvent-solvent attractions for dissolution to occur.

• For ionic solids in water, the positive ends of water dipoles attract anions, and the negative ends attract cations.

Solubility of Gases and Henry's Law

• Solubility of gases in water decreases with increasing temperature.

• Henry's Law: The solubility of a gas in a liquid is proportional to the pressure of the gas above the liquid.

Solubility of Solids

• Solubility of most solids in water increases with temperature.

Molarity Calculations

• Molarity (M):

• Example: To find the molarity of a solution, first convert grams to moles, then divide by volume in liters.

Chapter 14: Acids and Bases

Properties of Acids

• Acids taste sour, dissolve many metals, and turn blue litmus paper red.

Arrhenius and Bronsted-Lowry Definitions

• Arrhenius Acid: Produces H+ ions in aqueous solution (forms H3O+).

• Arrhenius Base: Produces OH- ions in aqueous solution.

• Bronsted-Lowry Acid: Proton donor.

• Bronsted-Lowry Base: Proton acceptor.

Acid-Base Reactions

• General products: Water and a salt.

• Conjugate acid-base pairs are formed in these reactions.

Chapter 17: Radioactivity and Nuclear Chemistry

Types of Radioactive Decay

• Alpha Decay: Emission of an alpha particle (mass number decreases by 4, atomic number decreases by 2).

• Beta Decay: Emission of a beta particle (mass number unchanged, atomic number increases by 1).

• Positron Emission: Atomic number decreases by 1.

• Gamma Radiation: No change in mass or atomic number.

Ionizing and Penetrating Power

Medical Applications of Nuclear Isotopes

• Technetium-99: Imaging internal organs.

• Phosphorus-32: Imaging tumors.

• Iodine-131: Diagnosing thyroid disorders.

• Gamma rays used in cancer treatment.

Chapter 18: Organic and Inorganic Compounds

Comparison of Organic and Inorganic Compounds

Hydrocarbons: Alkanes, Alkenes, Alkynes

• Alkane: General formula CnH2n+2 (e.g., C10H22).

• Alkene: General formula CnH2n.

• Alkyne: General formula CnH2n-2.

Alkyl Groups

• Methyl, ethyl, propyl, and isopropyl are common alkyl groups derived from alkanes by removing one hydrogen atom.

Chapter 19: Biomolecules

Carbohydrates

• Primary molecules for short-term energy storage.

• Monosaccharides: Simple sugars (e.g., glucose, fructose, galactose).

• Disaccharides: Two monosaccharides linked by glycosidic bonds.

• Polysaccharides: Many monosaccharides linked (e.g., starch, cellulose).

Lipids

• Insoluble in water, soluble in nonpolar solvents.

• Used for long-term energy storage and insulation.

• Fatty acids: Saturated (all single bonds) or unsaturated (at least one double bond).

• Triglycerides: Glycerol + 3 fatty acids (solid = saturated, liquid = unsaturated).

• Phospholipids: Glycerol, 2 fatty acids, phosphate group (amphipathic).

• Steroids: Four-ring structure (e.g., cholesterol, testosterone, estrogen).

Proteins

• Composed of amino acids linked by peptide bonds.

• Levels of structure:

  • Primary: Sequence of amino acids.

  • Secondary: Alpha helix and beta sheet (hydrogen bonding).

  • Tertiary: R group interactions (hydrogen bonds, disulfide bonds, hydrophobic interactions, salt bridges).

  • Quaternary: Arrangement of multiple polypeptide subunits.

DNA and Nucleic Acids

• Nucleic acids store genetic information (DNA and RNA).

• DNA: Double helix, deoxyribose sugar, bases A, T, C, G (A pairs with T, C pairs with G).

• RNA: Ribose sugar, bases A, U, C, G.

• Gene: Sequence of codons coding for a protein.

• Chromosome: Structure containing genes; humans have 46.