Chapter 20: Organic Chemistry
20.2: Hydrocarbons
- Hydrocarbons
- Organic compounds made entirely of carbon and hydrogen atoms.
- Saturated Hydrocarbons
- Hydrocarbons in which all bonds between carbon atoms are single bonds (also known as alkanes).
- Unsaturated Hydrocarbons
- Hydrocarbons with one or more double or triple bonds between carbon atoms (alkenes and alkynes).
- Aromatic Hydrocarbons
- Hydrocarbons containing ring structures with delocalized electrons (e.g., benzene).
Types of Hydrocarbons
- Alkanes: Contain only single bonds, with the general formula \(C_nH_{2n+2}\).
- Alkenes: Contain one or more double bonds, with the general formula \(C_nH_{2n}\).
- Alkynes: Contain one or more triple bonds, with the general formula \(C_nH_{2n-2}\).
- Aromatic Hydrocarbons: Contain stable ring structures, often based on benzene.
Properties of Hydrocarbons
- Nonpolar molecules.
- Low boiling and melting points compared to ionic compounds.
- Flammable and often used as fuels.
- Insoluble in water but soluble in nonpolar solvents.
Naming Hydrocarbons (IUPAC Rules)
- Identify the longest continuous carbon chain (parent chain).
- Number the chain starting from the end nearest a substituent.
- Name and number substituents attached to the parent chain.
- Combine the names of substituents with the parent chain name, using prefixes and proper numbering.
Questions for Students
- Define hydrocarbons and give examples of their different types.
- What is the difference between saturated and unsaturated hydrocarbons?
- List and explain the properties of hydrocarbons.
- What are the general formulas for alkanes, alkenes, and alkynes?
- Explain the basic rules for naming hydrocarbons using the IUPAC system.