Question

Draw a structural formula for each of the following. a. 3 -methylbutanoic acid b. 2 -chlorobenzoic acid c. hexanoic acid d. acetic acid

Short answer

a. The structural formula for 3-methylbutanoic acid is: \( CH_3CH_2CH(CH_3)COOH \) b. The structural formula for 2-chlorobenzoic acid is: \( o-ClC_6H_4COOH \) c. The structural formula for hexanoic acid is: \( CH_3(CH_2)_4COOH \) d. The structural formula for acetic acid is: \( CH_3COOH \)

Step-by-step solution

a. Drawing Structural Formula for 3-methylbutanoic acid

To draw the structural formula of 3-methylbutanoic acid, first, we need to determine the components of the molecule. 3-methylbutanoic acid consists of a 4-carbon chain as the butanoic acid part with a CH3 (methyl) group attached to the third carbon. The first carbon in this chain is attached to an OH group, making it a carboxylic acid. So, the structural formula for 3-methylbutanoic acid is: \( CH_3CH_2CH(CH_3)COOH \)

b. Drawing Structural Formula for 2-chlorobenzoic acid

To draw the structural formula of 2-chlorobenzoic acid, we first need to determine its basic structure, which is a benzene ring (6 carbon atoms connected in a ring with alternating single and double bonds). A chlorine (Cl) atom is attached to the second carbon, and a carboxylic acid (COOH) group is attached to the first carbon. The structural formula for 2-chlorobenzoic acid is: \( o-ClC_6H_4COOH \) Where "o-" denotes that the chlorine atom is attached to the ortho position (adjacent to the carboxylic acid group).

c. Drawing Structural Formula for hexanoic acid

To draw the structural formula for hexanoic acid, we first need to know that it consists of a 6-carbon chain with the last carbon being attached to an OH group, making it a carboxylic acid. The structural formula for hexanoic acid is: \( CH_3(CH_2)_4COOH \)

d. Drawing Structural Formula for acetic acid

To draw the structural formula for acetic acid, we need to know that it consists of a 2-carbon chain, with the second carbon being attached to an OH group, making it a carboxylic acid. The structural formula for acetic acid is: \( CH_3COOH \)

Key concepts

Understanding Organic Chemistry

Organic chemistry is a fascinating branch of science that studies the structure, properties, composition, reactions, and synthesis of carbon-containing compounds.
These compounds can include hydrogen, nitrogen, oxygen, and other areas of the periodic table. Organic chemistry is the foundation of many scientific fields, such as biochemistry, medicine, and materials science.

• Molecular Structure: Organic molecules consist of carbon backbones, which can be in the form of chains or rings with attached hydrogen atoms and various functional groups.


• Functional Groups: These are specific groups of atoms within molecules that determine their characteristic reactions. Examples include hydroxyl groups (-OH) and carboxyl groups (-COOH).


• Isomerism: This concept explains how molecules with the same molecular formula can have different structures and properties. Isomers are common in organic chemistry.

The diversity of organic compounds results from the amazing ability of carbon atoms to form four covalent bonds, allowing for branching and the formation of complex molecules.

Key Features of Carboxylic Acids

Carboxylic acids are a vital functional group in organic chemistry, recognized for their acidic properties. These compounds contain a carboxyl group (\(-COOH\)), which is a combination of a carbonyl group (C=O) and a hydroxyl group (-OH).
Here are some important aspects to understand:

• Acidity: Carboxylic acids are acidic because they can donate a proton (hydrogen ion) from their hydroxyl group. The remaining carboxylate ion is stabilized by resonance, making them more acidic compared to alcohols and phenols.


• Hydrogen Bonding: The -OH group allows carboxylic acids to form hydrogen bonds, leading to higher boiling and melting points compared to other organic molecules of similar size. This property affects their solubility in water.


• Common Examples: Acetic acid (vinegar) and citric acid (found in citrus fruits) are everyday examples of carboxylic acids that we encounter regularly.

Understanding how carboxylic acids react and interact with other chemicals is crucial for their role in metabolism, pharmaceuticals, and industrial processes.

Visualizing Chemical Structure Representation

Chemical structure representation is crucial in organic chemistry as it helps us understand and visualize how atoms are arranged within a molecule. This is essential for predicting properties and behaviors of different substances.
Some common forms of chemical representation include:

• Structural Formulas: These depict the exact arrangement and connectivity of atoms in a molecule. For instance, a structural formula of acetic acid illustrates its two carbon chain with the carboxyl group attached.


• Condensed Formulas: A simplified version where groups of atoms are written together, such as \(CH_3COOH\) for acetic acid, highlighting functional groups rather than every individual bond.


• Expanded Structural Formulas: Show every single bond between atoms, offering a more detailed view of the molecule's structure, which may be useful in understanding reactions.

Having a solid grasp of these representation styles is essential for anyone studying organic chemistry. They are the language that chemists use to communicate intricate details of molecular architecture.