Which of the following is not an isomer of $but-1-yne$?

Which of the following functional groups are functional isomers of esters?

What is functional group isomerism? Explain with a suitable example.

The compounds $CH_3COCH_3$ and $CH_2=C(OH)CH_3$ exhibit which of the following?

What is the minimum number of carbon atoms required to exhibit position isomerism in an organic compound?

Identify the pairs of compounds which are functional group isomers.
$I$. $CH_3-CH_2-CH_2-CH_2-OH$
$II$. $CH_3-CH_2-CH(OH)-CH_3$
$III$. $(CH_3)_3C-OH$
$IV$. $CH_3-CH(CH_3)-CH_2-OH$
$V$. $CH_3-CH_2-O-CH_2-CH_3$
$VI$. $CH_3-O-CH_2-CH_2-CH_3$
$VII$. $CH_3-O-CH(CH_3)_2$