Write $IUPAC$ and common name of the following:
$(i)$ $HCOOH$
$(ii)$ $CH_2Cl_2$
$(iii)$ $CHCl_3$
$(iv)$ $ClCH_2COOH$
$(v)$ $(COOH)_2$

The $IUPAC$ and common names are as follows:
$(i)$ $HCOOH$: $IUPAC$ name is $Methanoic \ acid$,Common name is $Formic \ acid$.
$(ii)$ $CH_2Cl_2$: $IUPAC$ name is $Dichloromethane$,Common name is $Methylene \ chloride$.
$(iii)$ $CHCl_3$: $IUPAC$ name is $Trichloromethane$,Common name is $Chloroform$.
$(iv)$ $ClCH_2COOH$: $IUPAC$ name is $2-Chloroethanoic \ acid$,Common name is $Chloroacetic \ acid$.
$(v)$ $(COOH)_2$: $IUPAC$ name is $Ethanedioic \ acid$,Common name is $Oxalic \ acid$.