The IUPAC name of $\mathrm{(CH_3)_2CHOH}$ is

1. Your syllabus: suffix '-ol' for alcohols, numbered to give the lowest locant to $\mathrm{-OH}$. 2. Structure: $\mathrm{CH_3{-}CH(OH){-}CH_3}$. The $\mathrm{-OH}$ is on the MIDDLE carbon. 3. Number the parent chain to give the $\mathrm{-OH}$ position lowest. The middle carbon of a 3-C chain is C2. 4. IUPAC name: PROPAN-2-OL (also written 2-propanol, common name isopropyl alcohol). 5. Option A is propan-1-ol ($\mathrm{CH_3CH_2CH_2OH}$). Option C is propanal $\mathrm{(CH_3CH_2CHO)}$ — aldehyde. Option D is propanoic acid — carboxylic acid. _Source: syllabus Chemistry Part 2, Ch 7, §7.1.2 (IUPAC Nomenclature, Examples Table 7.1), p. 2._