Compound $(B)$ is

In the given reaction sequence: $HOOC-CH_2-CH_2-COOH$ $\xrightarrow{\Delta} (A)$ $\xrightarrow{CH_3-CH_2-NH_2/\Delta} (B)$. $(B)$ will be:

The acid strength of the active methylene group in
$(a)$ $CH_3COCH_2COOC_2H_5$
$(b)$ $CH_3COCH_2COCH_3$
$(c)$ $C_2H_5OOCCH_2COOC_2H_5$
decreases as:

Provide the structure and common name for the $IUPAC$ names of the acids given in the table below:

Product $(X)$ is

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