Question

Carbon atoms appear in organic compounds in several different ways with single, double, and triple bonds combining to give an octet configuration. Describe the various ways that carbon can bond to reach an octet, and give the name and draw the structure of a compound that illustrates that mode of bonding.

Short answer

Carbon achieves an octet by forming single, double, or triple bonds as seen in methane, ethylene, and acetylene.

Step-by-step solution

Understanding Carbon Bonding

Carbon has four valence electrons and tends to form four covalent bonds to achieve a stable octet configuration. It can do so by forming single, double, or triple bonds with other carbon atoms or different elements.

Single Bonds Formation

In single bonds, carbon shares one pair of electrons with another atom. This allows carbon to bond with up to four other atoms using single bonds, as seen in methane (CH₄). Here, the carbon atom forms four single bonds with hydrogen atoms, achieving an octet.

Double Bonds Formation

Carbon can also form double bonds by sharing two pairs of electrons with another atom. An example is ethylene (C₂H₄), where each carbon atom forms a double bond with another carbon, and two single bonds with hydrogen, achieving an octet for each carbon.

Triple Bonds Formation

In triple bonds, carbon shares three pairs of electrons with another atom. An illustration of triple bonding between two carbon atoms is found in acetylene (C₂H₂), where each carbon forms a triple bond with the other and a single bond with hydrogen.

Illustration of Bond Types

To illustrate these bonds: - Methane: H—C—H in a tetrahedral structure. - Ethylene: H₂C=CH₂ in a planar structure. - Acetylene: HC≡CH in a linear structure.

Key concepts

Single Bonds in Organic Compounds

In organic compounds, a single bond is the simplest form of carbon bonding. It involves the sharing of one pair of electrons between two atoms, typically carbon and another non-metal such as hydrogen.
This type of bond is extremely versatile, enabling carbon to connect with four different atoms, usually in a tetrahedral arrangement. For instance, in methane (CH₄), carbon forms four single bonds, one with each hydrogen atom. This setup allows the carbon atom to achieve a stable octet by sharing its valence electrons effectively.
Single bonds are not only found in methane but in many other organic compounds, serving as a foundation upon which more complex structures can be built.

Double Bonds in Organic Chemistry

Double bonds involve the sharing of two pairs of electrons between atoms, often between carbon atoms themselves. This type of bond plays a crucial role in organic chemistry due to its ability to introduce diversity into molecular structures.
A great example of this is ethylene (C₂H₄). In ethylene, each carbon shares two electrons with the other, forming a double bond. Additionally, each carbon atom creates two single bonds with hydrogen atoms. This configuration leads to a planar structure which is characteristic of compounds with double bonds.
Double bonds introduce the ability for compounds to exhibit interesting properties, such as reactivity in addition reactions and the ability to create multiple forms, or isomers.

Triple Bonds in Carbon Compounds

Triple bonds form when three pairs of electrons are shared between two atoms, usually carbon atoms. This form of bonding results in an even stronger connection than double bonds, and they are typically characterized by linear structural arrangements.
Acetylene (C₂H₂) is a prime example of a compound with a triple bond. In acetylene, the two carbon atoms are connected by a triple bond, while each carbon is also bonded to a hydrogen atom through single bonds. This creates a linear molecule, unlike the bend seen in single and double-bonded arrangements.
Triple bonds are less common in nature than single or double bonds, yet they are tremendously significant in various industrial applications, including the production of synthetic chemicals and cutting industries due to their high energy release upon breaking.