Give the $IUPAC$ name and the functional group for each of the following compounds:
$(i)$ $CH_3CH_2CH_2CH_2COCl$
$(ii)$ $CH_3CH_2CN$
$(iii)$ $CH_3CH_2CHO$
$(iv)$ $CH_3CH_2CH_2OH$

(N/A) $(i)$ $CH_3CH_2CH_2CH_2COCl$: The functional group is $-COCl$ (Acyl chloride). The $IUPAC$ name is $pentanoyl$ $chloride$.
$(ii)$ $CH_3CH_2CN$: The functional group is $-CN$ (Nitrile). The $IUPAC$ name is $propanenitrile$.
$(iii)$ $CH_3CH_2CHO$: The functional group is $-CHO$ (Aldehyde). The $IUPAC$ name is $propanal$.
$(iv)$ $CH_3CH_2CH_2OH$: The functional group is $-OH$ (Alcohol). The $IUPAC$ name is $propan-1-ol$.