Problem 84 - Chemistry: The Central Science in SI Units, Global Edition

Question

If a molecule is an "ene-ol," what functional groups must it have? The suffix -ene signifies an alkene, \(-\) ol an alcohol. The molecule has alkene and alcohol functional groups.

Step-by-Step Solution

Answer

An "ene-ol" molecule has two functional groups: an alkene functional group, which consists of a carbon-carbon double bond (\(C=C\)), and an alcohol functional group, which consists of a hydroxyl group (\(-OH\)) bonded to a carbon atom.

Step 1: Identify the functional groups

From the given information, we can deduce that an "ene-ol" molecule must have two functional groups: 1. Alkene ("-ene") 2. Alcohol ("-ol")

Step 2: Describe the alkene functional group

The alkene functional group consists of a carbon-carbon double bond (\(C=C\)). The general formula for an alkene is \(C_nH_{2n}\), where 'n' is the number of carbon atoms in the molecule. Alkenes are unsaturated hydrocarbons, meaning they have at least one carbon-carbon double bond and can undergo additional reactions.

Step 3: Describe the alcohol functional group

The alcohol functional group consists of a hydroxyl group (\(-OH\)) bonded to a carbon atom. This functional group can be found in various organic compounds and imparts specific properties to the molecule, such as polarity and ability to hydrogen bond. The general structure of an alcohol is \(\text{R} - \text{OH}\), where 'R' represents the rest of the molecular structure. #Conclusion#: The molecule which is termed as an "ene-ol" must have both alkene and alcohol functional groups; alkene having a carbon-carbon double bond (\(C=C\)) and alcohol having a hydroxyl group (\(-OH\)) bonded to a carbon atom.

Key Concepts

Alkene

Alkenes are a key group of organic compounds that play an important role in chemistry. They are characterized by the presence of at least one carbon-carbon double bond, denoted as \(C=C\). This double bond is pivotal as it imparts unique properties to alkenes, distinguishing them from other hydrocarbons.

One of the most notable characteristics of alkenes is that they are unsaturated. This means they do not contain the maximum number of hydrogen atoms as possible, due to the presence of this double bond. The general formula for alkenes is \(C_nH_{2n}\), reflecting their ability to add more atoms through chemical reactions such as hydrogenation or halogenation.

Alkenes participate readily in reactions due to the reactivity of the double bond. These reactions can include addition reactions, where the double bond opens up to add new atoms or groups. This reactivity is what makes alkenes such a versatile group in the world of organic chemistry.

Alcohol Functional Group

The alcohol functional group is a distinctive feature in organic chemistry, characterized by its hydroxyl group \(-OH\) attached to a carbon atom. This group is common in a variety of organic molecules and is responsible for imparting certain unique properties to them.

The hydroxyl group brings polarity to the molecule because of the difference in electronegativity between oxygen and hydrogen, which allows alcohols to engage in hydrogen bonding. This interaction significantly impacts the physical properties of alcohols, such as their relatively high boiling points compared to non-polar molecules of similar molar mass.

The general structure of an alcohol is represented as \(\text{R} - \text{OH}\), where \(\text{R}\) indicates the hydrocarbon chain or the rest of the molecule that can vary widely in length and complexity. This structural diversity allows alcohols to be as straightforward as methanol or as complex as large polyhydric alcohols, each with distinct chemical behaviors and uses in industrial and biological contexts.

Hydroxyl Group

The hydroxyl group is a fundamental component of numerous organic molecules, especially in alcohols. It consists of an oxygen atom bonded to a hydrogen atom, represented chemically as \(-OH\). This small yet potent moiety is responsible for several key chemical properties observed in organic compounds.

Hydroxyl groups confer the ability to form hydrogen bonds, which is critical in determining solubility in water and other polar solvents. This bonding causes substances containing hydroxyl groups to be hydrophilic, meaning they are attracted to water. As a result, compounds like alcohols typically mix well with water, unlike their hydrocarbon counterparts.

This group also influences a molecule’s chemical reactivity. For example, it can be involved in dehydration reactions, forming other functional groups like alkenes. In addition, hydroxyl-bearing molecules often participate in oxidation-reduction reactions, making them valuable in both synthetic organic chemistry and natural biochemical processes.