Question

Each member of the following set of compounds is an alcohol; that is, each contains an - OH (hydroxyl group, Section 1.3A). Which line-angle formulas represent the same compound? Which represent constitutional isomers?

Short answer

a) Compounds 1 and 2 b) Compounds 2 and 3 c) Compounds 1 and 4 d) Compounds 2 and 4

Step-by-step solution

Identify the molecular structure of the compounds

Write out the structural formulas of the compounds based on the provided line-angle formulas. For instance, consider the hydroxyl group (-OH) and the carbon chain length. Do this for all the given compounds. In the case of our example set, the structures are: 1. CH3CH2CH2OH 2. CH3CH(OH)CH3 3. CH3CH2CH2OH 4. CH3CH2CH(OH)CH3

Compare each compound to the others

Examine the molecular structures of each compound and compare them with one another. Check if they are identical, have the same molecular formula but different connectivity (constitutional isomers), or are completely different alcohols. Create pairs of compounds that represent the same compound or constitutional isomers. For our example set, we can see: - Compounds 1 and 3 have the same molecular structure (CH3CH2CH2OH). - Compounds 2 and 4 have the same molecular formula (C4H10O) but different connectivity, making them constitutional isomers.

Classify the compounds

Based on the comparisons made in step 2, classify the compounds as being the same or constitutional isomers, as appropriate. For the example set, our classification would be: - Compounds 1 and 3 represent the same compound. - Compounds 2 and 4 are constitutional isomers.