Give the skeletal structure and name of the straight-chain alkanes whose molecular formula is shown.


(a) C₃H₈

Verified step by step guidance

1. Identify the number of carbon atoms in the molecular formula C₃H₈. There are 3 carbon atoms.
2. Recognize that the molecular formula C₃H₈ corresponds to an alkane, which is a saturated hydrocarbon with single bonds only.
3. Recall the general formula for alkanes, which is CₙH₂ₙ₊₂. For n = 3, the formula is C₃H₈, confirming it is an alkane.
4. Draw the skeletal structure of the alkane by arranging the 3 carbon atoms in a straight chain and adding hydrogen atoms to satisfy the valency of carbon (4 bonds per carbon).
5. Name the alkane based on the number of carbon atoms. For 3 carbon atoms, the name is 'propane'.

Key Concepts

Alkanes

Alkanes are a class of hydrocarbons characterized by single bonds between carbon atoms. They follow the general formula CnH2n+2, where 'n' is the number of carbon atoms. Alkanes are saturated compounds, meaning they contain the maximum number of hydrogen atoms per carbon atom, making them relatively stable and less reactive compared to unsaturated hydrocarbons.

Skeletal Structure

The skeletal structure of a molecule is a simplified representation that shows the arrangement of carbon atoms and the bonds between them, omitting hydrogen atoms for clarity. In skeletal structures, each vertex represents a carbon atom, and lines represent bonds. This representation helps in visualizing the molecular framework and understanding the connectivity of atoms in organic compounds.

Molecular Formula

A molecular formula indicates the number and types of atoms in a molecule, providing essential information about its composition. For example, C₃H₈ indicates that the molecule contains three carbon atoms and eight hydrogen atoms. This formula is crucial for identifying the specific alkane and determining its structural representation, as it directly relates to the number of carbon atoms in the straight-chain alkane.