Which of the following is picric acid?

Phenol $\xrightarrow{Zn \, \text{dust}} X$ $\xrightarrow[Anhyd. \, AlCl_3]{CH_3Cl} Y$ $\xrightarrow{\text{Alkaline } KMnO_4} Z$. In the above reaction,what is $Z$?

Explain why the alkoxy $(-OR)$ group is an ortho-para directing and ring-activating group for electrophilic aromatic substitution reactions.

The correct order of acidity of the above compounds is:

The increasing order of boiling points of the following compounds is:

The sequence of reactions is: $Phenol$ $\xrightarrow[\Delta]{Zn \, dust} X$ $\xrightarrow[\text{Anhydrous } AlCl_3]{CH_3Cl} Y$ $\xrightarrow[\Delta]{KMnO_4} Z$. The final product $Z$ is: