Give rules of nomenclature of organic compounds containing one or more functional groups.

(N/A) $(i)$ First of all,the functional group present in the molecule is identified,which determines the choice of the appropriate suffix.
$(ii)$ Longest parent chain: The longest chain of carbon atoms containing the functional group is numbered in such a way that the functional group is attached to the carbon atom possessing the lowest possible number in the chain.
$(iii)$ Polyfunctional compounds: In the case of polyfunctional compounds,one of the functional groups is chosen as the principal functional group,and the compound is then named on that basis. The remaining functional groups,which are subordinate,are named as substituents using appropriate prefixes.
$(iv)$ The choice of principal functional group is made on the basis of the order of preference. The order of decreasing priority for some functional groups is:
$-COOH > -SO_3H > -COOR > -COCl > -CONH_2 > -CN > -CHO > >C=O > -OH > -NH_2 > >C=C< > -C \equiv C-$
$(v)$ $-R, -C_6H_5$,halogens $(-F, -Cl, -Br, -I), -NO_2$,and alkoxy groups $(-OR)$ are always treated as prefix substituents.
$(vi)$ $A$ compound containing both an alcohol and a keto group is named as hydroxyalkanone since the keto group is preferred to the hydroxyl group. For example,$HOCH_2(CH_2)_3CH_2COCH_3$ is named as $7$-hydroxyheptan-$2$-one.
$(vii)$ If more than one functional group of the same type is present,their number is indicated by adding $di$,$tri$,etc.,before the class suffix. In such cases,the full name of the parent alkane is written before the class suffix. For example,$CH_2(OH)CH_2(OH)$ is named as ethane-$1,2$-diol.
$(viii)$ The ending $-e$ of the parent alkane is dropped in the case of compounds having more than one double or triple bond. For example,$CH_2=CH-CH=CH_2$ is named as buta-$1,3$-diene.