$A$ liquid was mixed with ethanol and a drop of concentrated $H_2SO_4$ was added. $A$ compound with a fruity smell was formed. The liquid was :

Arrange the following in decreasing order of their acidic strength: $C_6H_5COOH$,$FCH_2COOH$,$NO_2CH_2COOH$. Give an explanation for the arrangement.

Rearrange the following in the increasing order of acidic strength:
$(i)$ benzoic acid $(ii)$ $p$-methoxybenzoic acid $(iii)$ $o$-methoxybenzoic acid

Oxalic acid reacts with concentrated $H_2SO_4$ to produce a mixture of two gases. When this mixture is passed through caustic potash,one of the gases is absorbed. What substance is formed by the absorption of the gas in caustic potash?

When ethyl alcohol reacts with acetic acid,the products formed are

Identify $B$ in the following sequence of reactions.
Acetic acid $\xrightarrow[\Delta]{\text{Thionyl chloride}} A$ $\xrightarrow{\text{Ammonia}} B$