Question #44106

A $1.0 \text{ L}$ aqueous mixture contains $0.1 \text{ mol}$ of aniline, $0.1 \text{ mol}$ of $\ce{NaNO2}$, and $0.2 \text{ mol}$ of an amphiprotic salt $\ce{NaHA}$ (For $\ce{H2A}$, $pK_{a1} = 5.0$, $pK_{a2} = 9.0$). The mixture is placed in an adiabatic vessel initially at $273 \text{ K}$. To initiate diazotization, $0.2 \text{ mol}$ of $\ce{HCl}$ is rapidly added. The enthalpy of protonation of $\ce{HA-}$ to $\ce{H2A}$ is $-40 \text{ kJ mol}^{-1}$ and the enthalpy of the diazotization reaction is $-80 \text{ kJ mol}^{-1}$. The total heat capacity of the system is $250 \text{ J K}^{-1}$. After 15 minutes, an excess of alkaline $2$-naphthol is added to the vessel. What is the total number of $sp^2$ hybridized carbon atoms in the major organic product derived from aniline?