The isomeric alcohols with molecular formula C5H12O are :
(i) (a)

CH3CH2CH2CH2CH2OH

Pentanol(1°)

(b)

CH3CH2CH2 * C | OH HCH3

Pentan−2−ol(2°)

(c)

CH3CH2 C | OH HCH2CH3

Pentan−3−ol(2°)

(d)

H3CH2CH * C | CH3 CH2OH

2−Methylbutan−1−ol(1°)

(e)

CH3 CH3 | C HCH2CH2OH

3−Methylbutane−1−ol(1°)

(f)

CH3 CH3 | C | OH CH2CH3

2−Methylbutan−2−ol(3°)

(g)

CH3− CH3 | C | CH3 −CH2−OH

2,2−Dimethylpropan−1−ol(1°)

(h)

CH3− CH3 | C H− OH | C * H−CH3

3−Methylbutan−2−ol(2°)

Isomers (b), (d) and (h) contain chiral carbon atoms thus, they exhibit enantiomerism.
(ii) Isomers (a), (d), (e) and (g) are primary alcohols.
Isomers (b), (c) and (h) are secondary alcohols.
Isomer (f) is a tertiary alcohol.