Question

Give the systematic name of (a) \(\mathrm{CH}_{3} \mathrm{CH}\left(\mathrm{CH}_{3}\right) \mathrm{CH}_{2} \mathrm{COOH}\); (b) \(\mathrm{CH}_{2} \mathrm{ClCH}_{2} \mathrm{COOH}\); (c) \(\mathrm{CH}_{3}\left(\mathrm{CH}_{2}\right)_{7} \mathrm{COOH}\).

Short answer

(a) 3-Methylbutanoic acid; (b) 3-Chloropropanoic acid; (c) Octanoic acid

Step-by-step solution

Identify the Longest Carbon Chain and Its Length

For each compound, locate the longest continuous chain of carbon atoms that includes the carboxylic acid group (-COOH). Count the number of carbon atoms in that longest chain. This determines the base name of the compound in terms of the number of carbon atoms.

Number the Carbon Chain

Number the carbons in the longest chain beginning from the end closest to the functional group, which in this case is the carboxylic acid group (-COOH). The carbon in that group is always carbon-1.

Identify and Number Alkyl Substituents

Identify all substituents attached to the main carbon chain and determine their position (carbon number) along the chain. If a substituent is an alkyl group, use the appropriate prefix such as methyl, ethyl, etc., combined with the carbon number to show its position.

Construct the Systematic Name

Combine all parts of the name, starting with the substituents listed in alphabetical order, each prefixed with its position number, followed by the base name which is determined by the number of carbons in the main chain and ends with 'oic acid' to denote the carboxylic acid group.

Apply the Naming Process to Each Compound

Repeat the steps for each given compound to determine its systematic name. Be sure to include any necessary commas, dashes, and spaces in the name.

Key concepts

Chemical Nomenclature

Understanding chemical nomenclature is crucial for students and professionals in the field of chemistry. It's the systematic way of naming chemical compounds which allows chemists to communicate unambiguously about chemical substances. Students often face challenges with nomenclature because it requires learning a specific set of rules for naming compounds based on their molecular structure.

As an introduction, every compound's name serves as a description of its composition and structure. For instance, water, scientifically known as dihydrogen oxide, gives us the information that it consists of two hydrogen atoms and one oxygen atom. In organic chemistry, the naming of compounds becomes more intricate due to the vast number of possible structures. Hence, adopting a 'standard language' like the IUPAC naming conventions ensures consistency and clarity in the exchange of information.

Carboxylic Acid Naming

Carboxylic acids are a common functional group in organic molecules identified by the presence of a carboxyl group (-COOH). When naming carboxylic acids, the '-oic acid' suffix is characteristic and is indicative of this functional group. The approach to naming involves identifying the longest carbon chain that includes the carboxyl group and using the number of carbons to determine the root name.

For example, a carboxylic acid with a four-carbon chain is butanoic acid. If there are substituents such as chlorine or additional methyl groups attached to the chain, their presence and position are noted in the name. As a content creator, explaining this process step by step and with vivid examples can greatly aid students in mastering the concept.

IUPAC Naming Conventions

The International Union of Pure and Applied Chemistry (IUPAC) established a set of rules known as the IUPAC naming conventions. These guidelines allow the systematic naming of chemical compounds, including carboxylic acids. The key steps include identifying the longest carbon chain, numbering the chain starting from the end nearest to the carboxyl group, identifying and numbering substituents, and assembling the name with prefixes and suffixes in a particular order.

Students should pay special attention to these rules and practice them in various exercises to become proficient. Applying these conventions correctly will result in the unique and universally understood name for each compound.

Organic Chemistry

Organic chemistry is the study of carbon-containing compounds and their properties, structures, and reactions. Carboxylic acids are a fundamental topic within this discipline because they are widely prevalent in nature and in synthetically created substances. Grasping the concepts of organic chemistry, from the basics of carbon's bonding capabilities to the intricate systems of reactions and synthesis, is vital for students.

A solid foundation in understanding chemical bonds, functional groups, and isomerism, among other concepts, enables students to tackle the challenges of chemical nomenclature with confidence. Contextualizing the importance of systematic naming in organic chemistry could enhance their learning experience by showcasing its real-world applications.

Functional Groups Identification

Functional groups are specific groups of atoms within molecules that determine the chemical reactions of those molecules. Identifying functional groups is a core skill in organic chemistry, as they are key to predicting the behavior of organic substances. In carboxylic acids, the carboxyl (-COOH) group is the functional group of interest.

Teaching students to recognize functional groups supports their ability to predict physical and chemical properties. Effective instructions on this subject often include visual aids showing structural formulas and providing clear examples. With this knowledge, students can analyze various molecular structures and apply the IUPAC naming conventions appropriately to assign systematic names to organic compounds.