Which of the following is the correct $IUPAC$ name of catechol?

The number of isomers which are ethers and having the molecular formula $C_4H_{10}O$ is

What is the $IUPAC$ name of catechol?

Which of the following are known as mercaptans?

Which of the following is $NOT$ a phenol?

Write structures of the compounds whose $IUPAC$ names are as follows:
$(i)$ $2-$Methylbutan$-2-$ol
$(ii)$ $1-$Phenylpropan$-2-$ol
$(iii)$ $3,5-$Dimethylhexane$-1,3,5-$triol
$(iv)$ $2,3-$Diethylphenol
$(v)$ $1-$Ethoxypropane
$(vi)$ $2-$Ethoxy$-3-$methylpentane
$(vii)$ Cyclohexylmethanol
$(viii)$ $3-$Cyclohexylpentan$-3-$ol
$(ix)$ Cyclopent$-3-$en$-1-$ol
$(x)$ $4-$Chloro$-3-$ethylbutan$-1-$ol.