Which of the following is a pair of dihydric phenols?

Identify $A$ in the following reaction: $A + \text{Acetic anhydride} \xrightarrow{H^{+}} \text{Aspirin} + \text{Acetic acid}$

Arrange the following compounds in decreasing order of their acidic strength.

When phenol is reacted with $NH_3$ in the presence of $ZnCl_2$,what is the product formed?

The order of reactivity of phenol $(I)$,nitrobenzene $(II)$,and benzene $(III)$ towards nitration is:

The order of acidic strength of $X, Y$ and $Z$ is:
Phenol reacts with dilute $HNO_3$ to form $X$ ($o$-nitrophenol) and $Y$ ($p$-nitrophenol). Phenol reacts with concentrated $HNO_3$ and $H_2SO_4$ to form $Z$ ($2,4,6$-trinitrophenol or picric acid).