'A' and 'B' in the following reactions ($C_6H_5NH_2 \xrightarrow{CHCl_3/KOH} A \xrightarrow{H_2O/H^+} B$) are : 

In the following \(p\text{–}V\) diagram, the equation of state along the curved path is given by \[ (V-2)^2 = 4ap, \] where \(a\) is a constant. The total work done in the closed path is: 