Draw the line-angle formula for each of the following compounds:
c. 1,2,4-trichlorobenzene

Verified step by step guidance

1. Step 1: Understand the structure of benzene. Benzene is a six-membered aromatic ring with alternating double bonds. In a line-angle formula, it is represented as a hexagon with alternating double bonds inside the ring.
2. Step 2: Identify the substituents and their positions. The compound is 1,2,4-trichlorobenzene, which means there are three chlorine (Cl) atoms attached to the benzene ring at positions 1, 2, and 4.
3. Step 3: Assign position 1 to one of the vertices of the benzene ring. Then, moving clockwise or counterclockwise, assign position 2 to the adjacent vertex and position 4 to the vertex opposite position 1.
4. Step 4: Draw the benzene ring as a hexagon with alternating double bonds. Add a chlorine atom (Cl) at positions 1, 2, and 4 by drawing a line from the respective vertices of the hexagon to the Cl symbol.
5. Step 5: Verify the structure. Ensure that the benzene ring has alternating double bonds and that the chlorine atoms are correctly placed at positions 1, 2, and 4. This completes the line-angle formula for 1,2,4-trichlorobenzene.

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 drawing of complex structures, making it easier to visualize and understand molecular geometry.

Benzene and Substituents

Benzene is a cyclic hydrocarbon with a formula of C6H6, characterized by its stable ring structure and resonance. In compounds like 1,2,4-trichlorobenzene, chlorine atoms are substituents that replace hydrogen atoms on the benzene ring. The positions of these substituents are indicated by numbers, which refer to the carbon atoms in the ring. Understanding the placement of substituents is crucial for accurately drawing the line-angle formula.

Nomenclature of Aromatic Compounds

The nomenclature of aromatic compounds follows specific rules set by the International Union of Pure and Applied Chemistry (IUPAC). For 1,2,4-trichlorobenzene, the name indicates that three chlorine atoms are attached to the benzene ring at the first, second, and fourth carbon positions. Familiarity with these naming conventions is essential for interpreting chemical names and translating them into structural representations.