There are eight different five-carbon alkyl groups.
a. Draw them.
b. Give them systematic names.

Verified step by step guidance

1. Step 1: Understand that five-carbon alkyl groups are derived from alkanes with five carbon atoms, known as pentane. These groups are formed by removing one hydrogen atom from pentane, resulting in different structural isomers.
2. Step 2: Begin by drawing the straight-chain alkyl group, which is the n-pentyl group. This is derived from n-pentane, where the hydrogen is removed from the terminal carbon. The structure is CH₃(CH₂)₄−.
3. Step 3: Next, draw the branched isomers. Start with the isopentyl group, which is derived from isopentane. Remove a hydrogen from one of the terminal carbons, resulting in the structure (CH₃)₂CHCH₂CH₂−.
4. Step 4: Continue with the neopentyl group, derived from neopentane. Remove a hydrogen from one of the terminal carbons, resulting in the structure (CH₃)₄C−.
5. Step 5: Draw the remaining isomers by considering different branching patterns. For example, the sec-pentyl group is derived from removing a hydrogen from the secondary carbon in n-pentane, resulting in CH₃CH₂CH(CH₃)CH₂−. Repeat this process to identify all eight isomers, ensuring each has five carbon atoms and one open valency for bonding.

Key Concepts

Alkyl Groups

Alkyl groups are hydrocarbon chains that are derived from alkanes by removing one hydrogen atom, resulting in a structure that can attach to other molecules. In the context of the question, understanding the structure and naming of five-carbon alkyl groups is essential, as they form the basis for drawing and naming the compounds.

IUPAC Nomenclature

IUPAC nomenclature is the standardized system for naming chemical compounds, ensuring consistency and clarity in communication. For alkyl groups, this involves identifying the longest carbon chain, numbering the carbons to give substituents the lowest possible numbers, and naming the substituents accordingly. This concept is crucial for systematically naming the five-carbon alkyl groups.

Isomerism

Isomerism refers to the phenomenon where compounds have the same molecular formula but different structural arrangements. In the case of five-carbon alkyl groups, understanding isomerism is key to identifying all possible structural variations, including straight-chain and branched isomers, which must be drawn and named as part of the question.