Chapter 6: Ionic and Molecular Compounds

Symbols & Charges for Simple Ions of Representative Elements

Representative elements form ions by gaining or losing electrons to achieve a stable electron configuration, often resembling the nearest noble gas.

• Cations: Positively charged ions formed by loss of electrons (typically metals).

• Anions: Negatively charged ions formed by gain of electrons (typically nonmetals).

• Examples:

  • Sodium: Na → Na+

  • Chlorine: Cl → Cl-

  • Magnesium: Mg → Mg2+

  • Oxygen: O → O2-

Naming & Identifying Molecular & Ionic Compounds

Ionic compounds consist of metals and nonmetals, while molecular compounds are formed from nonmetals only.

• Ionic Compounds: Name the cation (metal) first, then the anion (nonmetal with -ide ending).

• Molecular Compounds: Use prefixes to indicate the number of each atom (e.g., carbon dioxide, dinitrogen monoxide).

• Example: NaCl is sodium chloride (ionic); CO2 is carbon dioxide (molecular).

Types of Bonds: Hydrogen Bonds, Ionic Bonds

• Ionic Bonds: Electrostatic attraction between oppositely charged ions.

• Hydrogen Bonds: A strong dipole-dipole attraction between a hydrogen atom bonded to N, O, or F and another electronegative atom.

• Example: NaCl forms ionic bonds; water molecules form hydrogen bonds with each other.

Predicting Three-Dimensional Structure of a Molecule

The shape of a molecule is determined by the number of bonding and lone pairs around the central atom (VSEPR theory).

• Linear: 2 electron groups (e.g., CO2)

• Trigonal Planar: 3 electron groups (e.g., BF3)

• Tetrahedral: 4 electron groups (e.g., CH4)

Anions & Cations

• Anion: Negatively charged ion (e.g., Cl-, O2-).

• Cation: Positively charged ion (e.g., Na+, Ca2+).

Chapter 11: Introduction to Organic Chemistry: Hydrocarbons

Properties of Organic & Inorganic Compounds

• Organic Compounds: Contain carbon, often covalent bonds, low melting/boiling points, flammable, soluble in nonpolar solvents.

• Inorganic Compounds: Often ionic, high melting/boiling points, nonflammable, soluble in water.

IUPAC Naming & Structure Identification for Alkanes, Alkenes, Cycloalkenes, & Alkynes

• Alkanes: Saturated hydrocarbons with single bonds. General formula:

• Alkenes: Unsaturated hydrocarbons with at least one double bond. General formula:

• Alkynes: Unsaturated hydrocarbons with at least one triple bond. General formula:

• Cycloalkenes: Cyclic hydrocarbons with double bonds.

• Naming: Use the longest carbon chain containing the functional group; number to give the lowest possible numbers to double/triple bonds.

• Example: CH2=CH-CH3 is propene (alkene).

Saturated & Unsaturated Hydrocarbons

• Saturated: Only single bonds (alkanes).

• Unsaturated: Contains double or triple bonds (alkenes, alkynes).

Cis-Trans Isomers

Cis-trans isomerism occurs in alkenes due to restricted rotation around the double bond.

• Cis: Similar groups on the same side of the double bond.

• Trans: Similar groups on opposite sides.

• Example: 2-butene can exist as cis-2-butene and trans-2-butene.

Structural Formula of Benzene

• Benzene: Aromatic hydrocarbon with six carbon atoms in a ring and alternating double bonds.

• Formula:

• Structure: Often represented as a hexagon with a circle inside to denote delocalized electrons.

Combustion & Addition Reactions

• Combustion: Hydrocarbons react with O2 to produce CO2 and H2O. Equation:

• Addition: Atoms are added to the carbons of a double or triple bond (e.g., hydrogenation, halogenation).

• Example: Ethene + H2 → Ethane (hydrogenation).

Chapter 12: Alcohols, Thiols, Ethers, Aldehydes, and Ketones

IUPAC Naming, Structures, & Structural Formulas

• Alcohols: Contain -OH group. Classified as primary (1°), secondary (2°), or tertiary (3°) based on the number of alkyl groups attached to the carbon with the -OH.

• Phenols: Hydroxyl group attached to a benzene ring.

• Ethers: Oxygen atom connected to two alkyl or aryl groups (R-O-R').

• Thiols: Contain -SH group.

• Aldehydes: Carbonyl group (C=O) at the end of a carbon chain.

• Ketones: Carbonyl group (C=O) within the carbon chain.

• Naming: Use the parent hydrocarbon name, change the suffix as appropriate (e.g., -ol for alcohols, -al for aldehydes, -one for ketones).

• Example: CH3CH2OH is ethanol (alcohol); CH3CHO is ethanal (aldehyde).

Solubility in Water

• Alcohols, aldehydes, and ketones with short carbon chains are soluble in water due to hydrogen bonding.

• Solubility decreases as the hydrocarbon chain length increases.

Tollens' Test

• Tollens' reagent is used to distinguish aldehydes from ketones.

• Positive result: Aldehydes reduce Tollens' reagent to metallic silver ("silver mirror").

• Ketones do not react with Tollens' reagent.

Table: Classification of Alcohols

Additional info: Academic context and examples have been added to clarify and expand upon the brief points in the original study guide.