The boiling points to isomeric alcohols follow the order

Alcohols with same molecular weight ate expected to have almost same boiling point, however two more factors other than molecular weight are important; they are namely H-bonding and surface area of molecule. Both these factors are least in 3∘alcohols and maximum in 1∘alcohols. Hence, 3∘alcohols have least boiling point while 1∘alcohols have maximum boiling point