Alcohols are alcohols having the general structure r₃coh. (or oxiranes) are cyclic ethers having the oxygen atom as part of a three-membered ring. have a hydroxy group as a substituent on a benzene ring. alcohols are alcohols having the general structure rch₂oh. have two alkyl groups bonded to an oxygen atom. have an oh group on a carbon of a c-c double bond. alcohols are alcohols having the general structure r₂choh.

Tertiary alcohols are alcohols having the general structure R₃COH.

Epoxides (or oxiranes) are cyclic ethers having the oxygen atom as part of a three-membered ring.

Phenols have a hydroxy group as a substituent on a benzene ring.

Primary alcohols are alcohols having the general structure RCH₂OH.

Ethers have two alkyl groups bonded to an oxygen atom.

Enols have an OH group on a carbon of a C-C double bond.

Secondary alcohols are alcohols having the general structure R₂CHOH.

Explanation:

Alcohols are then classified into primary, secondary and tertiary, based upon the number of carbon atoms connected to the carbon atom that bears the hydroxyl functional group.

If the carbon has only one alkyl group bond to the carbon that bears the hydroxyl functional group, it is a primary alcohol. (R-CH₂-OH)

If the carbon has two alkyl group bonded to the carbon that bears the hydroxyl functional group, it is a secondary  alcohol. (R₂-CH-OH)

If the carbon has three alkyl group bonded to the carbon that bears the hydroxyl functional group, it is a tertiary alcohol. (R₃-C-OH)

An epoxide is a cyclic ether with a three-atom ring. This ring approximates an equilateral triangle, which makes it strained, and hence highly reactive, more so than other ethers.

Phenol is an aromatic organic compound with the molecular formula C₆H₅OH. The molecule consists of a phenyl group (−C₆H₅) bonded to a hydroxy group (−OH).

Ethers are a class of organic compounds that contain an ether group—an oxygen atom connected to two alkyl or aryl groups.

Enols are a type of reactive structure or intermediate in organic chemistry that is represented as an alkene with a hydroxyl group attached to one end of the alkene double bond.

i believe you are right for all except the 3rd ( look at sqdancefan his answer is much better)