Draw the line-angle formula for each of the following:
a. 3-methylheptane

Verified step by step guidance

1. Step 1: Understand the structure of the compound. The name '3-methylheptane' indicates that the main chain is 'heptane,' which consists of 7 carbon atoms connected in a straight chain with single bonds (an alkane).
2. Step 2: Identify the substituent. The '3-methyl' part of the name indicates that there is a methyl group (-CH₃) attached to the third carbon atom of the heptane chain.
3. Step 3: Draw the main chain. Using the line-angle formula, represent the 7-carbon chain of heptane as a zigzag line with 7 vertices. Each vertex represents a carbon atom, and the ends of the line also represent carbon atoms.
4. Step 4: Add the substituent. Starting from one end of the chain, count to the third carbon atom. Attach a short line to this vertex to represent the methyl group (-CH₃).
5. Step 5: Verify the structure. Ensure that each carbon atom has the correct number of bonds (4 total, including bonds to hydrogen atoms not explicitly shown in the line-angle formula) and that the substituent is correctly placed on the third carbon.

Key Concepts

Line-Angle Formula

The line-angle formula, also known as the skeletal formula, is a shorthand representation of organic molecules. In this format, vertices represent carbon atoms, and lines represent bonds between them. Hydrogen atoms are typically omitted for carbon atoms, as they are implied by the tetravalency of carbon. This method simplifies the visualization of complex structures, making it easier to identify functional groups and molecular geometry.

Alkanes

Alkanes are a class of hydrocarbons characterized by single bonds between carbon atoms, following the general formula CnH2n+2. They are saturated compounds, meaning they contain the maximum number of hydrogen atoms per carbon atom. The structure of alkanes can be linear or branched, and understanding their nomenclature is essential for drawing their line-angle formulas. For example, 3-methylheptane is a branched alkane derived from heptane with a methyl group attached to the third carbon.

IUPAC Nomenclature

The International Union of Pure and Applied Chemistry (IUPAC) nomenclature provides a systematic method for naming organic compounds. It establishes rules for identifying the longest carbon chain, naming substituents, and indicating their positions on the chain. For 3-methylheptane, the name indicates a seven-carbon chain (heptane) with a methyl group on the third carbon. Familiarity with IUPAC rules is crucial for accurately interpreting and drawing chemical structures.