Question

Complete and rewrite the balanced chemical equation for the following reactions: 
a. \[\ce{1-chloro-2, 4-dinitrobenzene ->[aq. alkali][368 K, H+]}\] ?

b. \[\ce{Benzaldehyde ->[50‰ KOH] }\] ?

c. \[\ce{Acetone + phenylhydrazine ->[H+]}\] ?

Answer 1

1.  When l-chloro-2, 4-dinitrobenzene is heated with aqueous alkali (aq. NaOH ), 2, 4-dinitro sodium phenoxide is formed which on hydrolysis with dilute HCl gives 2, 4-dinitrophenol.
   
2. Two molecules of benzaldehyde react in the presence of 50‰ KOH, the products formed are benzyl alcohol and potassium benzoate. The reaction is called cannizzaro reacion.
3. Acetone reacts with phenyl hydrazine to give addition product which on dehydration gives acetone phenyl hydrazone. This reaction occurs in the presence of an acid catalyst.
   \[\begin{array}{cc}
   \ce{CH3}\phantom{................................}\ce{CH3}\phantom{................................}\\
   \backslash\phantom{................................}\backslash\phantom{.............................}\\
   \ce{\underset{\text{Phenyl hydrazine}}{C = O + H2N - NH - C6H5} ->[H+] \underset{\text{Acetone phenyl hydrazone}}{C = N - NH - C6H5 + H2O}}\\
   /\phantom{................................}/\phantom{............................}\\
   \ce{\underset{\text{Aceton}}{CH3}}\phantom{................................}\ce{CH3}\phantom{..............................}
   \end{array}\]