1. Phenol treated with conc. \( HNO_3 \):
Phenol reacts with concentrated nitric acid (\( HNO_3 \)) to form a mixture of nitrophenols. The reaction is as follows:
\[
C_6H_5OH + HNO_3 \to 2,4,6 - \text{Nitrophenol} + H_2O
\]
2. Propene treated with \( B_2H_6 \) followed by oxidation by \( H_2O_2 / OH^- \):
The hydroboration-oxidation reaction of propene results in the formation of an alcohol:
\[
C_3H_6 + B_2H_6 \to C_3H_7B \quad \text{(Hydroboration)}
\]
Followed by oxidation:
\[
C_3H_7B + H_2O_2 / OH^- \to C_3H_7OH \quad \text{(Propan-2-ol)}
\]
3. Sodium t-butoxide treated with \( CH_3Cl \):
Sodium t-butoxide undergoes nucleophilic substitution with methyl chloride to form t-butyl methyl ether:
\[
(CH_3)_3CO^- + CH_3Cl \to (CH_3)_3COCH_3
\]