when p-chlorobenzaldehyde undergo cannazarro reaction need to reflux and heating, but p-nitrobenzaldehyde the reaction takes place at at room temperature (where, NO2 and Cl are withdrawing groups)
when p-chlorobenzaldehyde undergo cannazarro reaction need to reflux and heating, but p-nitrobenzaldehyde the reaction takes place at at room temperature (where, NO2 and Cl are withdrawing groups)










