Question

Draw the two isomers of chloropropane, \(\mathrm{C}_{3} \mathrm{H}_{7} \mathrm{Cl}\).

Short answer

The two isomers of chloropropane are 1-chloropropane and 2-chloropropane.

Step-by-step solution

Understand Isomers

Isomers are compounds with the same molecular formula but different structural arrangements. Here, we are drawing isomers of chloropropane, each having the formula \(\mathrm{C}_{3}\mathrm{H}_{7}\mathrm{Cl}\). This means the arrangement of atoms will differ between isomers while comprising 3 carbon atoms, 7 hydrogen atoms, and 1 chlorine atom.

Draw the Straight-Chain Chloropropane

Start by drawing the three-carbon chain (propane structure). Replace a hydrogen atom on either of the terminal carbon atoms with a chlorine atom to get the first isomer. This is 1-chloropropane, with chlorine bonded to the first carbon in the chain: \[ \mathrm{CH}_3\mathrm{CH}_2\mathrm{CH}_2\mathrm{Cl} \].

Draw the Branched-Chain Chloropropane

For the second isomer, replace a hydrogen atom on the middle carbon (the second carbon atom) with a chlorine atom. This gives the second isomer, 2-chloropropane, which has chlorine attached to the second carbon in the chain: \[ \mathrm{CH}_3\mathrm{CH(Cl)}\mathrm{CH}_3 \].

Key concepts

Chloropropane

In chemistry, chloropropane is a type of alkyl halide, where a chlorine atom substitutes a hydrogen atom in the propane molecule. Propane, a simple hydrocarbon, forms the backbone for chloropropane. By replacing one hydrogen with a chlorine atom, we derive our molecule, chloropropane. This modification plays a crucial role in transforming the properties of the molecule, making chloropropane crucial in chemical synthesis and various industrial applications.
Understanding the nature of chloropropane helps in comprehending how slight changes in atomic configuration affect a compound's behavior and reactivity. For instance, when a chlorine atom replaces a hydrogen atom in propane, it often increases the molecule's reactivity, which can be crucial in processes like organic synthesis or in the production of other organic compounds.

Structural Arrangement

The concept of structural arrangement refers to how the atoms within a molecule are organized to create different structural isomers. In chloropropane, even though both isomers share the same molecular formula \( \mathrm{C}_3\mathrm{H}_7\mathrm{Cl} \), their physical and chemical properties vary due to their different structures.
For chloropropane specifically, there are two main isomers based on the carbon atom to which the chlorine atom is attached:

• 1-chloropropane where the chlorine atom is attached to the first carbon atom.
• 2-chloropropane where the chlorine atom is connected to the second carbon atom, creating a slight branch in the chain.

These structural differences affect factors like boiling and melting points, density, and chemical reactivity. Structural isomerism highlights how even minor rearrangements within a molecule can lead to entirely different chemical species.

Chlorine Atom Attachment

In the context of chloropropane isomers, the attachment point of the chlorine atom determines the type of isomer we have. This simple change profoundly influences the compound's properties.
In 1-chloropropane, the chlorine atom is attached to the terminal carbon, resulting in a linear structure. Here, the chlorine's presence on the end carbon can affect how the molecule interacts with other compounds, like affecting its boiling point or reactivity.
In contrast, 2-chloropropane has the chlorine atom connected to the middle carbon atom. This subtlest change in attachment, from the end to the middle of the chain, results in different chemical behaviors. It can affect things like the molecule's symmetry, how it might participate in chemical reactions, and the ways it can be used in industry or laboratory settings.
Understanding attachment is crucial for chemists who need to predict or manipulate how compounds will react under specific conditions.