Question

There are three compounds with the formula \(\mathrm{C}_{6} \mathrm{H}_{3} \mathrm{Cl}_{3}\) in which three of the hydrogen atoms of the benzene molecule have been replaced by chlorine atoms. Draw structures for these compounds.

Short answer

Question: Draw and describe the three possible structures for compounds with the formula \(\mathrm{C}_{6} \mathrm{H}_{3} \mathrm{Cl}_{3}\), in which three hydrogen atoms of the benzene molecule have been replaced by chlorine atoms. Answer: The three possible structures for the compounds with the formula \(\mathrm{C}_{6} \mathrm{H}_{3} \mathrm{Cl}_{3}\) formed by replacing three hydrogen atoms of the benzene molecule with chlorine atoms are ortho, meta, and para isomers of chlorinated benzene. 1. Ortho chlorinated benzene: In this structure, the chlorine atoms are directly adjacent to each other on the benzene ring. ``` Cl | C // \ C C //| |\ Cl--C C--Cl \| |// C C \\ // C | Cl ``` 2. Meta chlorinated benzene: In this structure, the chlorine atoms are separated by one carbon atom on the benzene ring. ``` Cl | C // \ C C //| |\ H -C C --Cl \| |// C C \\ // C | Cl ``` 3. Para chlorinated benzene: In this structure, the chlorine atoms are opposite each other on the benzene ring. ``` Cl | C // \ C C //| |\ H -C C --Cl \| |// C C \\ // C | Cl ```

Step-by-step solution

Understanding the benzene molecule structure

Benzene is a six-carbon ring molecule with alternating single and double bonds and a hydrogen atom bonded to each carbon. Each carbon in benzene is sp2 hybridized, and the molecule has a planar structure with each carbon-carbon bond angle approximately equal to 120 degrees. The carbon and hydrogen atoms in benzene are represented as \(\mathrm{C}_{6} \mathrm{H}_{6}\).

Identify the possible positions for replacing hydrogen with chlorine

To form compounds with the formula \(\mathrm{C}_{6} \mathrm{H}_{3} \mathrm{Cl}_{3}\), three hydrogen atoms on the benzene ring need to be replaced by chlorine atoms. The positions of the chlorine atoms on the benzene ring will determine the structure of these compounds. In general, there can be three possible arrangements for the chlorine atoms on the benzene ring: ortho, meta, and para positions, which correspond to the chlorine atoms being adjacent, separated by one carbon, and opposite each other in the ring, respectively.

Draw ortho chlorinated benzene structure

In the ortho-arrangement, the chlorine atoms are directly adjacent to each other. To draw this structure, start by sketching the benzene ring with the three adjacent carbon atoms bearing the chlorine atoms. The ortho-chlorinated benzene structure is as follows: ``` Cl | C // \ C C //| |\ Cl--C C--Cl \| |// C C \\ // C | Cl ```

Draw meta chlorinated benzene structure

In the meta-arrangement, the chlorine atoms are separated by one carbon atom. To draw this structure, start by sketching the benzene ring with the chlorine atoms on alternating carbon atoms. The meta-chlorinated benzene structure is as follows: ``` Cl | C // \ C C //| |\ H -C C --Cl \| |// C C \\ // C | Cl ```

Draw para chlorinated benzene structure

In the para-arrangement, the chlorine atoms are opposite each other on the benzene ring. To draw this structure, start by sketching the benzene ring with the three chlorine atoms in positions that are opposite each other. The para-chlorinated benzene structure is as follows: ``` Cl | C // \ C C //| |\ H -C C --Cl \| |// C C \\ // C | Cl ``` Now, we have drawn the three possible structures for the compounds with the formula \(\mathrm{C}_{6} \mathrm{H}_{3} \mathrm{Cl}_{3}\) formed by replacing three hydrogen atoms of the benzene molecule with chlorine atoms. These three structures represent the ortho, meta, and para isomers of chlorinated benzene.