Organic compounds are those that contain carbon, and they form the basis of all life forms on Earth. Carbon compounds can be classified into different types based on their structures and properties, including alkanes, alkenes, alkynes, aromatics, alcohols, ethers, ketones, aldehydes, carboxylic acids, esters, amines, amides, and polymers.
Carbon compounds have a wide range of applications in various fields such as medicine, agriculture, energy, and industry. For example, hydrocarbons are used as fuels, such as gasoline and diesel, and as feedstocks for the production of chemicals and plastics. Carbon compounds are also important in the production of pharmaceuticals, fragrances, and flavors.
The study of carbon compounds and their properties is known as organic chemistry. Organic chemists use various techniques to synthesize and study new carbon compounds, including spectroscopy, chromatography, and crystallography. The discovery and development of new carbon compounds have revolutionized our world and continue to play a critical role in our lives.
BONDING IN CARBON – THE COVALENT BOND
Carbon typically forms covalent bonds with other atoms, which involves the sharing of electrons between the atoms. Covalent bonding is the most common type of chemical bonding for carbon.
In a covalent bond, each atom contributes one or more electrons to a shared pair of electrons, forming a molecule. The shared electrons are attracted to both nuclei, holding the atoms together in the molecule. The number of covalent bonds an atom can form depends on the number of electrons it has available for bonding.
In carbon, the outermost shell contains four electrons, allowing it to form up to four covalent bonds. This is because carbon has four valence electrons in its outermost shell and requires four more electrons to complete its octet, the stable electron configuration of eight valence electrons.
Carbon can form covalent bonds with other carbon atoms, as well as with other elements such as hydrogen, oxygen, nitrogen, and halogens. In organic compounds, carbon atoms are often bonded to other carbon atoms, forming long chains and complex structures.
The strength of covalent bonds between atoms depends on various factors, such as the number of shared electrons and the distance between the nuclei. Covalent bonds are generally strong and require a significant amount of energy to break.
In summary, covalent bonding is the most common type of chemical bonding for carbon, involving the sharing of electrons between atoms to form a molecule. Carbon can form up to four covalent bonds, allowing for the formation of a vast array of carbon compounds with diverse properties and applications.
Melting points and boiling points of some compounds of carbon
The melting and boiling points of compounds of carbon can vary widely depending on their molecular structure, intermolecular forces, and other factors. Here are some examples of the melting and boiling points of different types of carbon compounds:
- Alkanes: These are hydrocarbons with single bonds between carbon atoms. They have low melting and boiling points because of their weak intermolecular forces, which are only van der Waals forces. For example, methane (CH4) has a boiling point of -161.5°C and a melting point of -182.5°C.
- Alkenes: These are hydrocarbons with at least one double bond between carbon atoms. They have higher melting and boiling points than alkanes because the double bond introduces some polarity in the molecule. For example, ethene (C2H4) has a boiling point of -103.7°C and a melting point of -169°C.
- Alkynes: These are hydrocarbons with at least one triple bond between carbon atoms. They have higher melting and boiling points than alkenes because the triple bond introduces even more polarity in the molecule. For example, ethyne (C2H2) has a boiling point of -84°C and a melting point of -80.8°C.
- Alcohols: These are organic compounds containing a hydroxyl (-OH) group. They have higher melting and boiling points than hydrocarbons because the -OH group can form hydrogen bonds with neighboring molecules. For example, methanol (CH3OH) has a boiling point of 64.7°C and a melting point of -97.6°C.
- Carboxylic acids: These are organic compounds containing a carboxyl (-COOH) group. They have higher melting and boiling points than alcohols because they can form even stronger hydrogen bonds. For example, acetic acid (CH3COOH) has a boiling point of 118.1°C and a melting point of 16.6°C.
- Aromatic compounds: These are compounds that contain a ring of carbon atoms with alternating single and double bonds. They have higher melting and boiling points than other hydrocarbons because of their planar structure and delocalized electrons. For example, benzene (C6H6) has a boiling point of 80.1°C and a melting point of 5.5°C.
Overall, the melting and boiling points of carbon compounds can vary widely depending on their molecular structure and other factors. However, some general trends can be observed based on the types of bonds and functional groups present in the compound.
Triple bond between two nitrogen atom
A triple bond between two nitrogen atoms is a type of covalent bond that is formed when two nitrogen atoms share three pairs of electrons with each other. This type of bond is very strong and requires a large amount of energy to break. The triple bond between two nitrogen atoms is commonly found in nitrogen gas (N2), which is the most abundant gas in Earth’s atmosphere. The triple bond between the nitrogen atoms in N2 gives the molecule its stability and makes it difficult for other molecules to react with it. The molecular formula of nitrogen gas is N≡N, where the triple bond between the two nitrogen atoms is represented by three lines.
Double bond between two oxygen atoms
A double bond between two oxygen atoms is a type of covalent bond that is formed when two oxygen atoms share two pairs of electrons with each other. This type of bond is relatively strong and requires a significant amount of energy to break. The double bond between two oxygen atoms is commonly found in molecules such as oxygen gas (O2), ozone (O3), and organic compounds containing oxygen, such as aldehydes and ketones.
The molecular formula of oxygen gas is O=O, where the double bond between the two oxygen atoms is represented by two lines. In this case, each oxygen atom shares two electrons with the other oxygen atom, forming a total of four shared electrons. The double bond between the two oxygen atoms in oxygen gas gives the molecule its stability and makes it difficult for other molecules to react with it.
In ozone (O3), there are three oxygen atoms, with one double bond between two of the oxygen atoms and a single bond between the third oxygen atom and one of the double-bonded oxygen atoms. The molecular formula of ozone is O=O-O, where the double bond is represented by two lines and the single bond is represented by one line. The double bond between the two oxygen atoms in ozone also contributes to the molecule’s stability and reactivity.
- The electron dot structure of carbon dioxide (CO2) would be:
-
O O
════ C ════
║ ║
O O
In this structure, the central carbon atom shares two pairs of electrons with each of the two oxygen atoms. Each oxygen atom has two lone pairs of electrons.
The electron dot structure of a molecule of sulfur made up of eight atoms of sulfur (S8) would be:
S S S S S S S S
║ ║ ║ ║ ║ ║ ║
S–S–S–S–S–S–S–S
VERSATILE NATURE OF CARBON
Carbon is a versatile element due to its ability to form strong covalent bonds with other carbon atoms and with atoms of other elements, such as hydrogen, oxygen, nitrogen, and sulfur. The covalent bonds between carbon atoms can form a variety of structures, including straight chains, branched chains, and rings. This ability of carbon to form a wide range of structures and bond with multiple elements makes it the foundation for all known life on Earth.
The versatile nature of carbon is the basis of organic chemistry, which is the study of the chemistry of carbon compounds. Carbon compounds, also known as organic compounds, include a vast array of substances, such as carbohydrates, lipids, proteins, nucleic acids, and many more. These compounds are found in all living organisms and play essential roles in biological processes such as metabolism, energy storage, and genetic information transfer.
Furthermore, the versatile nature of carbon has also led to the development of numerous synthetic materials, such as plastics, synthetic fibers, and drugs. Carbon-based materials have a wide range of properties and can be engineered to have specific properties suited for different applications.
Overall, the versatile nature of carbon has made it an essential element for life and technology, and its unique ability to form a wide range of structures and bond with multiple elements has led to a vast array of applications and innovations.
Saturated and Unsaturated Carbon Compounds
Saturated and unsaturated carbon compounds are two broad categories of organic compounds based on the presence or absence of double or triple bonds between carbon atoms.
Saturated carbon compounds, also known as alkanes, are organic compounds that contain only single covalent bonds between carbon atoms. These compounds have the maximum number of hydrogen atoms attached to each carbon atom, and their general formula is CnH2n+2. Examples of saturated carbon compounds include methane (CH4), ethane (C2H6), propane (C3H8), and butane (C4H10).
Unsaturated carbon compounds, on the other hand, are organic compounds that contain at least one double or triple bond between carbon atoms. These compounds have fewer hydrogen atoms attached to each carbon atom than saturated carbon compounds. Unsaturated carbon compounds can be further divided into two subcategories based on the number of double or triple bonds:
- Alkenes: These are unsaturated hydrocarbons that contain at least one carbon-carbon double bond. Their general formula is CnH2n, and examples include ethene (C2H4) and propene (C3H6).
- Alkynes: These are unsaturated hydrocarbons that contain at least one carbon-carbon triple bond. Their general formula is CnH2n-2, and examples include ethyne (C2H2) and propyne (C3H4).
Unsaturated carbon compounds are generally more reactive than saturated carbon compounds due to the presence of double or triple bonds, which can undergo addition reactions with other molecules. They are also commonly used in organic synthesis to create more complex molecules.
In summary, saturated carbon compounds have only single bonds between carbon atoms, while unsaturated carbon compounds have at least one double or triple bond between carbon atoms. Alkenes contain carbon-carbon double bonds, while alkynes contain carbon-carbon triple bonds.