$($Elliott $3\mathrm{.}6)$ Chlorobenzene $(l)$ is produced by reacting benzene $(l)$ initially at

$30C$ with $C{l}_2(g)$ initially at $30C$ in a batch reactor using $AIC{I}_3$ as a catalyst.

$HCl(g)$ is a by$-$product. During the course of the reaction, the temperature

increases to $50C.$ To avoid dichlorobenzenes, conversion of benzene is lim$-$

ited to $30\%.$ On the basis of $1$mol of benzene, and $0\mathrm{.}5motC{l}_2(g)$ feed, what

heating or cooling is required using the specified method$($s$)?$ The NIST Web$-$

Book reports the heats of formation for liquid benzene and chlorobenzene at

$25C$ as $49k\frac{J}{m}ol$ and $11\mathrm{.}5k\frac{J}{m}ol,$ respectively. The heat capacities of liquid

benzene and chlorobenzene are $136\frac{J}{m}ol-K$ and $150\frac{J}{m}ol-K,$ respectively.

$($a$)$ Use liquid reference states for the benzenes and the heat of reaction

method for the energy balance. $($Answer: $Q=35\mathrm{.}9kJ)$

$($b$)$ Follow part $($a$),$ but instead, use the heat of formation method for the

energy balance.