Question

(a) What do the terms saturated and unsaturated mean? (b) Draw an example of a saturated four carbon compound and an unsaturated four carbon compound.

Short answer

Saturated compounds have only single bonds, while unsaturated have at least one double or triple bond. Examples: Saturated - butane (C4H10); Unsaturated - 1-butene (C4H8).

Step-by-step solution

Understanding Saturated Compounds

Saturated compounds are organic molecules that only contain single bonds between carbon atoms. This usually allows them to have the maximum number of hydrogen atoms attached, making them highly stable. Alkanes are typical examples of saturated compounds.

Understanding Unsaturated Compounds

Unsaturated compounds include at least one double or triple bond between carbon atoms. This configuration means that these compounds have fewer hydrogen atoms than their saturated counterparts and are usually more reactive. Alkenes and alkynes are types of unsaturated compounds.

Drawing a Saturated Four-Carbon Compound

An example of a saturated four-carbon compound is butane. It has the chemical formula \( C_4H_{10} \), with the structure: \( \text{CH}_3-\text{CH}_2-\text{CH}_2-\text{CH}_3 \). All the carbon atoms are connected by single bonds, and each carbon is fully saturated with hydrogen atoms.

Drawing an Unsaturated Four-Carbon Compound

An example of an unsaturated four-carbon compound is 1-butene, which contains a double bond. Its chemical formula is \( C_4H_8 \) with the structure: \( \text{CH}_2=\text{CH}-\text{CH}_2-\text{CH}_3 \). The double bond between the first and second carbon atoms indicates its unsaturated nature.

Key concepts

Saturated Compounds

Saturated compounds are an important category in organic chemistry. These compounds are characterized by having only single bonds between their carbon atoms. As a result, they can hold the maximum number of hydrogen atoms. This configuration makes them highly stable.
They generally resist reacting with other substances unless under strong conditions.
Saturated compounds typically belong to a group called alkanes.

• Alkanes include simple molecules like methane, ethane, and larger ones like butane.
• They follow the general formula: \( C_nH_{2n+2} \), meaning their hydrogen count is always twice the number of carbons, plus two.

This stability makes alkanes valuable as fuels and in various industrial applications. Understanding saturated compounds also helps in grasping more complex reactions and molecular behaviors.

Unsaturated Compounds

Unlike saturated compounds, unsaturated compounds contain at least one double or triple bond between the carbon atoms. This feature makes them more reactive and open to chemical reactions, such as additions.
They do not have the maximum amount of hydrogens due to these bonds.
Alkenes and alkynes are the primary types of unsaturated compounds.

• Alkenes have one or more double bonds, such as ethene and propene.
• Alkynes have one or more triple bonds, such as acetylene.

The presence of multiple bonds in alkenes and alkynes means they can easily react with substances like halogens or hydrogen.
Their reactivity leads to important chemical processes like polymerization, which is crucial for creating plastics.

Alkanes and Alkenes

Alkanes and alkenes are key groups within organic chemistry that represent different types of hydrocarbons. Alkanes, as mentioned before, are fully saturated hydrocarbons.
They have single carbon–carbon bonds and are typically less reactive.
Alkenes, on the other hand, contain at least one carbon-to-carbon double bond, making them unsaturated.

• They are more reactive than alkanes because the double bond can participate in various chemical reactions.
• This reactivity of alkenes is often used in chemical syntheses and industrial processes.

Examples include:
- Butane (alkane): \( C_4H_{10} \) is a typical saturated hydrocarbon.
- 1-Butene (alkene): \( C_4H_8 \) includes a double bond making it reactive.
Both groups play essential roles in organic chemistry and are the basis for understanding complex hydrocarbon structures.

Carbon Bonds

Carbon bonds form the framework of organic chemistry, enabling the vast diversity of carbon-based compounds. They exist in various types: single, double, and triple bonds, each influencing the molecule's properties and reactivity.
Single bonds are prevalent in saturated compounds and are strong and stable.
Double bonds signify unsaturation, found in alkenes, providing sites for additional chemical reactions.

• Triple bonds take this unsaturation further, as seen in alkynes, leading to even higher reactivity.
• Dual functionality can occur where multiple bond types exist within the same molecule, creating varied reaction pathways.

The molecular flexibility provided by these bonds allows carbon to form chains, rings, and complex frameworks.
This adaptability is why carbon is the backbone of organic compounds, supporting life's molecular diversity.