Give the skeletal structure and name of the straight-chain alkanes whose molecular formula is shown.
(a) C₃H₈

Verified step by step guidance

1. Step 1: Understand the problem. The molecular formula C₃H₈ represents a straight-chain alkane. Alkanes are hydrocarbons that consist only of single bonds between carbon atoms and follow the general formula CₙH₂ₙ₊₂.
2. Step 2: Determine the number of carbon atoms in the molecule. The subscript '3' in C₃H₈ indicates there are three carbon atoms in the molecule.
3. Step 3: Arrange the carbon atoms in a straight chain. In a straight-chain alkane, the carbon atoms are connected in a linear sequence without branching.
4. Step 4: Add hydrogen atoms to satisfy the valency of carbon. Each carbon atom forms four bonds, so add enough hydrogen atoms to ensure each carbon has four bonds in total.
5. Step 5: Name the alkane. The prefix 'prop-' is used for three carbon atoms, and the suffix '-ane' indicates it is an alkane. Therefore, the name of the compound 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 format helps in visualizing the molecular framework and is commonly used in organic chemistry to depict complex molecules succinctly.

Molecular Formula

A molecular formula indicates the number and type of atoms in a molecule, providing essential information about its composition. For example, C₃H₈ indicates a molecule with three carbon atoms and eight hydrogen atoms, which corresponds to propane, a straight-chain alkane. Understanding molecular formulas is crucial for identifying the structure and properties of organic compounds.