What is the major product of the following reaction?

In Column-$I$ formula,in Column-$II$ general name and in Column-$III$ $IUPAC$ name are given. Match the items in Column-$I$ with the appropriate items in Column-$II$ and Column-$III$.

Column-$I$ (Formula)	Column-$II$ (General Name) and Column-$III$ ($IUPAC$ Name)
$(A)$ $HCOOH$	$(i)$ Succinic acid,$(x)$ Methanoic acid
$(B)$ $CH_3CH_2CH_2COOH$	$(ii)$ Oxalic acid,$(y)$ Ethanedioic acid
$(C)$ $(COOH)_2$	$(iii)$ Formic acid,$(m)$ Butanedioic acid
$(D)$ $(CH_2)_2(COOH)_2$	$(iv)$ Butyric acid,$(n)$ Butanoic acid

Which compound on oxidation with acidic $KMnO_4$ gives Benzoic acid?

Provide identification tests for the following pairs of compounds:
$(1)$ Phenol and carboxylic acid
$(2)$ Formic acid and acetic acid
$(3)$ Acetic acid and ethanol
$(4)$ Acetic acid and acetone
$(5)$ Aldehyde and ketone
$(6)$ Acetaldehyde and acetone
$(7)$ Acetaldehyde and formaldehyde
$(8)$ Benzaldehyde and acetaldehyde

Identify the major product of the reaction when the given compound is hydrolyzed and heated strongly.

The acidity of compounds $I-IV$ in water follows the order:
$I.$ ethanol
$II.$ acetic acid
$III.$ phenol
$IV.$ acetonitrile