What is the correct structure of 4-octane?
The Correct Answer and Explanation is:
The correct structure of 4-octane is a straight-chain alkane with eight carbon atoms, where the fourth carbon atom has a single bond to a methyl group (–CH3). This is based on the IUPAC nomenclature system for organic compounds, where “octane” indicates an 8-carbon chain and the “4” represents the position of the branching group.
Structure Details:
- The molecule consists of 8 carbon atoms (C8) bonded by single covalent bonds, each having the maximum number of hydrogen atoms attached to them to satisfy the carbon valency of four.
- The longest chain (carbon backbone) is the octane chain (C8), which is a saturated alkane, meaning each carbon atom in the chain is bonded to the maximum number of hydrogen atoms (no double or triple bonds).
- At the fourth carbon atom (C4), there is a methyl group (–CH3) attached. This gives the molecule its name “4-octane.”
Molecular Formula:
The molecular formula for 4-octane is C8H18, indicating that it contains 8 carbon atoms and 18 hydrogen atoms.
Structural Representation:
The structure can be written as:
scssCopyEditCH3-CH2-CH2-CH(CH3)-CH2-CH2-CH3
- The first carbon (C1) is bonded to three hydrogens (–CH3).
- The second (C2) and third (C3) carbons are bonded to two hydrogens each (–CH2–).
- The fourth carbon (C4) is bonded to a methyl group (–CH3) and a –CH2– group.
- The rest of the chain continues similarly with alternating –CH2– groups until the eighth carbon (C8), which is also bonded to three hydrogens (–CH3).
This structure represents a saturated hydrocarbon with no double or triple bonds and is stable due to the single covalent bonds between carbon atoms. This is typical of alkanes, where the carbons are sp³ hybridized, and the molecule adopts a tetrahedral geometry.
