Step 1: Read the two targets. Picric acid needs three -\(NO_2\) groups added to the ring; benzoquinone needs the ring oxidised to a diketone. So one step is nitration, the other is oxidation.
Step 2: Making picric acid. Because the phenolic -OH is a powerful o/p activator, heating phenol with concentrated nitric acid together with concentrated sulphuric acid drives trinitration.
\(C_6H_5OH + 3HNO_3 \rightarrow C_6H_2(NO_2)_3OH + 3H_2O\)
The yellow solid formed is 2,4,6-trinitrophenol, i.e. picric acid.
Step 3: Making benzoquinone. Oxidising phenol with an acidified dichromate (or chromic acid) removes hydrogens from the 1- and 4-positions and installs two carbonyls, giving p-benzoquinone \(C_6H_4O_2\).
\(C_6H_5OH \xrightarrow{[O]} C_6H_4O_2\)
Step 4: Result. Nitration route yields picric acid and oxidation route yields benzoquinone.
\[\boxed{\text{picric acid by nitration; benzoquinone by oxidation}}\]