How do you distinguish between isomers when naming?

Isomers are distinguished when naming by their structural differences, functional groups, and the position of these groups.

Isomers are compounds that have the same molecular formula but different structural formulas. This means they have the same number and type of atoms, but these atoms are arranged differently. When naming isomers, it's important to take into account these structural differences. The International Union of Pure and Applied Chemistry (IUPAC) has established rules for naming organic compounds, including isomers.

The first step in distinguishing isomers is to identify the longest carbon chain in the molecule, which forms the base name of the compound. For example, a six-carbon chain would be named 'hexane'. If the isomers have different lengths of carbon chains, they will have different base names.

Next, identify any functional groups present in the molecule. Functional groups are specific groupings of atoms within molecules that have their own characteristic properties. Common functional groups include alcohols (-OH), aldehydes (-CHO), ketones (C=O), and carboxylic acids (-COOH). The presence and type of functional group will affect the name of the isomer. For example, an isomer of hexane with an alcohol group would be named 'hexanol'.

Finally, the position of the functional group on the carbon chain is also important in distinguishing isomers. The position is indicated by a number in the name of the compound. For example, '2-hexanol' indicates that the alcohol group is on the second carbon atom in the chain.

In summary, when naming isomers, you need to consider the length of the carbon chain, the type and presence of functional groups, and the position of these groups on the chain. By following the IUPAC rules, you can accurately name and distinguish between different isomers.