Question

Give two examples of saturated hydrocarbons. How many other atoms are bonded to each carbon in a saturated hydrocarbon?

Short answer

Two examples of saturated hydrocarbons are methane (CH4) and ethane (C2H6). In a saturated hydrocarbon, each carbon atom forms four bonds. The number of other atoms bonded to each carbon depends on its position in the molecule: a carbon with no adjacent carbon atoms will bond with four hydrogen atoms; a carbon with one adjacent carbon atom will bond with one carbon and three hydrogen atoms; and a carbon with two adjacent carbon atoms will bond with two carbon and two hydrogen atoms.

Step-by-step solution

Understand the concept of saturated hydrocarbons

Saturated hydrocarbons, also known as alkanes, are organic compounds that consist only of carbon (C) and hydrogen (H) atoms, with each carbon atom forming single bonds with hydrogen atoms and other carbon atoms. The general formula for saturated hydrocarbons is \( C_nH_{2n+2} \), where n is the number of carbon atoms in the compound.

Provide two examples of saturated hydrocarbons

We can use the general formula of saturated hydrocarbons, \( C_nH_{2n+2} \), to provide examples of alkanes. For example, by plugging in n=1 and n=2, we can find two simple saturated hydrocarbons: 1. Methane (CH4): When n=1, we have \( C_1H_{2(1)+2}=CH_4\). 2. Ethane (C2H6): When n=2, we have \( C_2H_{2(2)+2}=C_2H_6\).

Determine the number of other atoms bonded to each carbon in a saturated hydrocarbon

In saturated hydrocarbons, all the carbon atoms form single bonds with hydrogen atoms and other carbon atoms. Each carbon atom is tetravalent, meaning it must form four bonds. Therefore, in a saturated hydrocarbon, the number of other atoms bonded to each carbon atom will depend on how many carbon atoms are adjacent to that carbon. 1. For a carbon atom with no adjacent carbon atoms (only one carbon in the compound): - Example: Methane (CH4) - The carbon atom is bonded to 4 hydrogen atoms. 2. For a carbon atom with one adjacent carbon atom (two carbons in the compound), e.g., an end carbon in a longer chain: - Example: Ethane (C2H6) - The carbon atom is bonded to 1 carbon atom and 3 hydrogen atoms. 3. For a carbon atom with two adjacent carbon atoms (inside carbons in a longer chain): - Example: Propane (C3H8) - The middle carbon atom is bonded to 2 carbon atoms and 2 hydrogen atoms. In summary, each carbon atom in a saturated hydrocarbon will always be bonded to four other atoms, which might be a combination of carbon and hydrogen atoms depending on their position in the molecule.

Key concepts

Alkanes

Alkanes, often referred to as saturated hydrocarbons, form the simplest family within organic chemistry. They are composed exclusively of carbon and hydrogen atoms interconnected by single bonds—a characteristic that gives them the 'saturated' designation, meaning they have the maximum number of hydrogen atoms attached to each carbon atom. The general molecular formula for alkanes is \( C_nH_{2n+2} \), where \( n \) represents the number of carbon atoms.

For example, methane, with the molecular formula \( CH_4 \), is the simplest alkane and consists of a single carbon atom bonded to four hydrogen atoms. Ethane, with the formula \( C_2H_6 \), has two carbon atoms, each bonded to three hydrogens, and a single bond connecting the two carbon atoms. As the hydrocarbon chain grows, more carbon atoms join the sequence, always maintaining the four bonds to either hydrogen or neighboring carbon atoms.

Alkanes exhibit a variety of physical properties that vary based on their molecular size. Their uses in the industry are also vast, including being fuels and lubricants, and they serve as foundational structures for more complex organic compounds.

Organic Chemistry

Organic chemistry is a vast and dynamic field of chemistry focusing on the compounds of carbon. This branch of chemistry came about with the realization that carbon-based compounds, which are foundational to life, exhibit a diverse array of structures and functions. In organic compounds, carbon can form stable bonds with itself and other elements like hydrogen, oxygen, nitrogen, and more, leading to an immense variety of molecules.

In the context of organic molecules, the term 'organic' refers to the carbon-based backbone of these compounds. This is because carbon has a unique ability to form chains and rings of atoms, allowing for the complexity and diversity seen in organic molecules. \( sp^3 \) hybridization in carbon atoms is crucial for forming the single bonds in alkanes. Organic chemistry not only explores hydrocarbons like alkanes but also encompasses understanding functional groups, isomerism, and chemical reactions that lead to the synthesis of complex molecules with specific properties.

Chemical Bonding

Chemical bonding is fundamental to the structure of all molecules, including alkanes. A bond is formed by the attraction between two atoms, which can share, donate, or accept electrons to achieve greater stability, generally guided by the octet rule in which atoms tend to have eight electrons in their valence shell, resembling a noble gas configuration.

In saturated hydrocarbons, carbon atoms exhibit \( sp^3 \) hybridization, where one s-orbital and three p-orbitals combine to form four equivalent hybrid orbitals, each capable of forming a single sigma (σ) bond with hydrogen or other carbon atoms. The versatility of carbon allows it to form long chains and rings bound by these covalent bonds, which are typified by the sharing of electron pairs between atoms.

The tetravalency of carbon—its ability to form four bonds—results in a tetrahedral geometry around each carbon atom in alkanes. These single bonds lead to a molecule that is fully saturated with hydrogen, and therefore, more stable and less reactive than their unsaturated counterparts, which contain double or triple bonds and can react more readily with other substances.