Question

Draw the condensed structural formulas for all the possible alkane isomers that have a total of six carbon atoms and a four- carbon chain.

Short answer

Isomers with six carbons and a four-carbon chain are 3-Methylpentane and 2,3-Dimethylbutane.

Step-by-step solution

- Understand the Problem

You need to find all possible alkane isomers with six carbon atoms. Each isomer must include a straight four-carbon chain.

- Identify the Base Chain

Start with a linear four-carbon chain, which is butane: C-C-C-C

- Add Remaining Carbon Atoms

Given that we have six carbon atoms total and have used four for the base chain, we need to add two more carbon atoms. They must be placed as branches to create different isomers.

- Draw 3-Methylpentane

Attach one carbon atom to the third carbon of the butane chain: CH3-CH2-CH(CH3)-CH2-CH3. This is 3-Methylpentane.

- Draw 2,3-Dimethylbutane

Next, place the two remaining carbon atoms as methyl groups on the second and third carbon of the base chain: CH3-CH(CH3)-CH(CH3)-CH3. This is 2,3-Dimethylbutane.

Key concepts

condensed structural formulas

Condensed structural formulas provide a shorthand way to represent the structure of chemical compounds. Instead of drawing every single bond between atoms, chemists use this notation to show how atoms are connected more efficiently. For example, instead of drawing each bond in a butane molecule, we write it as CH3-CH2-CH2-CH3. This keeps the structural formula concise and easier to read. Condensed formulas are especially useful for representing isomers quickly. Since isomers can have the same molecular formula but different connections between atoms, using condensed structural formulas helps in distinguishing these variations clearly.

six carbon atoms

One key aspect of our exercise is dealing with molecules that have six carbon atoms. These atoms can be linked in various ways to form different isomers. For instance, hexane is a straight-chain alkane with the formula C6H14. But there are several other structures with six carbon atoms that qualify as isomers. By exploring these structures, we gain insight into the versatility of carbon chains in organic chemistry. Identifying and drawing these different configurations helps us understand how atoms can rearrange to form compounds with different properties, despite having the same number of carbon and hydrogen atoms.

four-carbon chain

A four-carbon chain forms the backbone of the isomers we are considering. This core chain is butane, represented as C-C-C-C. Chains like this serve as the skeleton upon which other atoms or groups are added. In the exercise, we use a butane chain and add other carbon atoms to it. By doing so, we create different structural isomers. Visualizing the main chain is essential for a solid understanding of organic molecules' structures. Remember, the position where additional carbon atoms are attached alters the compound significantly, creating distinct isomers with unique properties.

alkane isomers

Alkane isomers are different compounds that have the same molecular formula but different structures. For six-carbon alkanes, we can have several isomers. In the context of the exercise, two specific isomers featured are 3-Methylpentane and 2,3-Dimethylbutane. 3-Methylpentane (CH3-CH2-CH(CH3)-CH2-CH3) has a main chain of five carbons with a methyl group attached to the third carbon. On the other hand, 2,3-Dimethylbutane (CH3-CH(CH3)-CH(CH3)-CH3) is a four-carbon chain with two methyl groups attached to the second and third carbons. Learning about these and practicing drawing them aids in mastering the concept of structural isomers in organic chemistry.