The number of chiral alcohol(s) with molecular formula C$$_4$$H$$_{10}$$O is ______ (Assume stereoisomers as different chiral alcohols)

We need to find the number of chiral alcohols with molecular formula C$$_4$$H$$_10$$O, counting stereoisomers as different. The possible alcohol isomers are 1. 1-Butanol: CH$$_3$$CH$$_2$$CH$$_2$$CH$$_2$$OH; 2. 2-Butanol: CH$$_3$$CH(OH)CH$$_2$$CH$$_3$$; 3. 2-Methyl-1-propanol (Isobutanol): (CH$$_3$$)$$_2$$CHCH$$_2$$OH; 4. 2-Methyl-2-propanol (tert-Butanol): (CH$$_3$$)$$_3$$COH.

A chiral center is a carbon bonded to four different groups. In 1-butanol no carbon has four different groups, so it is not chiral. In 2-butanol carbon-2 is bonded to OH, H, CH$$_3$$, and CH$$_2$$CH$$_3$$ — four different groups, making it chiral with two stereoisomers: (R)-2-butanol and (S)-2-butanol. In 2-methyl-1-propanol no carbon has four different groups, so it is not chiral. In 2-methyl-2-propanol the central carbon has three identical CH$$_3$$ groups, so it is not chiral.

Only 2-butanol is chiral, and it has two stereoisomers. Since stereoisomers are counted as different chiral alcohols, the answer is 2.