Which of the following compounds does $NOT$ contain a phenolic $-OH$ group?

Ethyl methyl ether is .....

Which of the following is a tertiary benzylic alcohol?

Write $IUPAC$ names of the following compounds:
$(i)$ $CH_3-CH(CH_3)-CH(OH)-C(CH_3)_2-CH_3$
$(ii)$ $CH_3-CH(OH)-CH_2-CH(OH)-CH(C_2H_5)-CH_2-CH_3$
$(iii)$ $CH_3-CH(OH)-CH(OH)-CH_3$
$(iv)$ $HO-CH_2-CH(OH)-CH_2-OH$
$(v)$ $2-Methylphenol$ (structure)
$(vi)$ $4-Methylphenol$ (structure)
$(vii)$ $2,5-Dimethylphenol$ (structure)
$(viii)$ $2,6-Dimethylphenol$ (structure)
$(ix)$ $CH_3-O-CH_2-CH(CH_3)-CH_3$
$(x)$ $C_6H_5-O-C_2H_5$
$(xi)$ $C_6H_5-O-C_7H_{15}(n-)$
$(xii)$ $CH_3-CH_2-O-CH(CH_3)-CH_2-CH_3$

The total number of structural isomeric alcohols with the molecular formula $C_4H_{10}O$ is $:-$

Identify the functional group present in ethers from the following.