Question

What is the name of the straight (unbranched) chain alkane with the formula \(\mathrm{C}_{7} \mathrm{H}_{16} ?\)

Short answer

The alkane is called heptane.

Step-by-step solution

Identify the Formula

The given molecular formula is \(\mathrm{C}_{7} \mathrm{H}_{16}\). Identify it as an alkane based on the formula \(\mathrm{C}_{n} \mathrm{H}_{2n+2}\). This indicates it is a saturated hydrocarbon with only single bonds.

Determine the Number of Carbon Atoms

Count the number of carbon atoms in the formula. In \(\mathrm{C}_{7} \mathrm{H}_{16}\), the subscript 7 indicates there are 7 carbon atoms.

Name the Alkane

Using the IUPAC nomenclature system for alkanes, the prefix for 7 carbon atoms is 'hept'. Since this is a straight chain alkane, add the suffix 'ane' to the prefix, resulting in the name 'heptane'.

Key concepts

IUPAC naming

The IUPAC naming system, formulated by the International Union of Pure and Applied Chemistry, provides a standard method for naming chemical compounds. This system ensures that each compound has a unique and standardized name, avoiding confusion and improving communication among chemists worldwide. Understanding this system is essential for naming organic compounds correctly.

The IUPAC naming structure typically includes three parts:

• A prefix, which provides information about the substituents attached to the main carbon chain.
• A root word, indicating the number of carbon atoms in the longest continuous chain.
• A suffix, highlighting the main functional group or nature of the compound, such as 'ane' for alkanes.

In the example of the molecule \((\mathrm{C}_{7}\mathrm{H}_{16})\), IUPAC naming helps us to derive the name 'heptane', since 'hept-' refers to seven carbons, and '-ane' indicates that it is an alkane.

straight-chain alkanes

Straight-chain alkanes are hydrocarbons where carbon atoms are connected in a linear chain. They contain no branches, which means every carbon atom is attached sequentially, forming a simple straight line of carbon atoms. Understanding their structure is crucial because this linearity affects both their physical and chemical properties.

For the alkane \((\mathrm{C}_{7}\mathrm{H}_{16})\), the term straight-chain indicates all 7 carbon atoms line up in a row, without side branches. Such simplicity in structure typically results in higher melting and boiling points compared to their branched counterparts with similar molecular weights, due to the increased surface area for van der Waals interactions. Recognizing the pattern in naming also helps understand their properties better.

saturated hydrocarbons

Saturated hydrocarbons are organic compounds that contain only single bonds between carbon atoms. This structure is fully "saturated" with hydrogen atoms, which makes them stable and relatively less reactive compared to unsaturated hydrocarbons that contain double or triple bonds.

Alkanes, including the molecule \((\mathrm{C}_{7}\mathrm{H}_{16})\), belong to the class of saturated hydrocarbons. The general formula for an alkane is \(\mathrm{C}_{n}\mathrm{H}_{2n+2}\), which accounts for the maximum number of hydrogen atoms that can bond with the carbon skeleton. Because of this full saturation with hydrogen, such alkanes participate mainly in combustion reactions or undergo substitution reactions under more extreme conditions, such as the presence of UV light. Their saturated nature makes these hydrocarbons critical as basic fuels and feedstocks in various industrial applications.