Question

Write the condensed structural formula for each of the following compounds: (a) 2 -ethyl-1-hexanol, (b) methyl phenyl ketone, (c) para-bromobenzoic acid, (d) butyl ethyl ether, (e) \(N,N\)-dimethylbenzamide.

Short answer

(a) \(CH_3CH_2CH(OH)CH_2CH(CH_3)CH_3\) (b) \(CH_3CO(C_6H_5)\) (c) \(C_6H_4BrCOOH\) (d) \(C_4H_9OC_2H_5\) (e) \(C_6H_5CON(CH_3)_2\)

Step-by-step solution

(a) 2-ethyl-1-hexanol

First, let's find out the main chain's structure. The compound's name implies that it is an alcohol, and the base of the name "hexanol" indicates that there are six carbon atoms in the main chain. The alcohol functional group, -OH, is present at position 1. We also have an ethyl substituent at position 2. The condensed structural formula can be written as follows: \(CH_3CH_2CH(OH)CH_2CH(CH_3)CH_3\).\newline

(b) methyl phenyl ketone

Methyl phenyl ketone is a ketone with a methyl group and a phenyl group attached to the carbonyl carbon. Phenyl refers to a benzene ring (\(C_6H_5\)) and methyl means \(CH_3\). The ketone, therefore, has a condensed structural formula of \(CH_3CO(C_6H_5)\).\newline

(c) para-bromobenzoic acid

Para-bromobenzoic acid is a benzoic acid derivative with a bromine atom para to the carboxylic acid group. Benzoic acid has a benzene ring with a carboxylic acid group attached (\(C_6H_5COOH\)). Para position implies that the bromine atom is present at position 4 on the ring. The condensed formula for para-bromobenzoic acid is: \(C_6H_4BrCOOH\).\newline

(d) butyl ethyl ether

Butyl ethyl ether is an ether with a butyl group (\(C_4H_9\)) and an ethyl group (\(C_2H_5\)) attached to the oxygen atom. In condensed form, it can be represented as \(C_4H_9OC_2H_5\).\newline

(e) \(N,N\)-dimethylbenzamide

Benzamide is an amide where the carboxylic acid group in benzoic acid is replaced by the amide group, i.e., \(C_6H_5CONH_2\). In this compound, both hydrogen atoms on the nitrogen atom have been replaced by methyl (\(CH_3\)) groups, making it an \(N,N\)-dimethyl benzamide. The condensed formula for \(N,N\)-dimethylbenzamide is: \(C_6H_5CON(CH_3)_2\).

Key concepts

Organic Chemistry

Organic chemistry is a profound and fascinating branch of chemistry that focuses on compounds of carbon. This field explores the structures, properties, compositions, reactions, and preparation of carbon-containing compounds, which includes not only hydrocarbons but also compounds with any number of other elements, including hydrogen, nitrogen, oxygen, halogens, phosphorus, silicon, and sulfur.

Because carbon atoms can form stable bonds with many other atoms including other carbon atoms, organic chemistry provides a wide range of molecular configurations. This allows for the creation of a vast array of compounds with diverse chemical properties, making organic chemistry central to many industries including pharmaceuticals, petrochemicals, food, explosives, and paints.

Understanding the basics of organic chemistry is essential for interpreting the structural formulas of organic molecules, which is the key focus when determining how molecules will interact and react with each other.

Functional Groups

Functional groups are specific groupings of atoms within molecules that have their own characteristic properties. These properties will largely determine the molecule's chemical reactivity and physical properties.

Every organic molecule contains one or more functional groups. Examples include alcohols which contain the hydroxyl group (-OH), ketones with the carbonyl group (C=O), and carboxylic acids with the carboxyl group (COOH). The identification of functional groups is an essential skill in organic chemistry, as it informs predictions about the behavior of molecules.

Functional groups can behave predictably in chemical reactions, which is why knowing these groupings helps when synthesizing new compounds or deducing the structure of an unknown substance through analytical techniques.

Structural Representation

The structural representation of a molecule provides a means to visualize its molecular structure, which is vital for understanding its function and reactivity. In organic chemistry, various forms of structural representation are used to simplify and convey information about molecular structures efficiently.

The 'condensed structural formula' is a form of representation that shows the arrangement of atoms in a molecule. While less detailed than the full structural formula, the condensed version groups atoms together in a way that highlights the functional groups and the connectivity between them, without showing all the individual bonds.

This type of representation is useful for quickly conveying information about the molecule's makeup and for writing chemical equations that otherwise would be cumbersome with full structural diagrams. Learning to interpret these formulas is an essential skill for students, allowing them to understand and predict the behavior of organic compounds.