URGENT $,$ PLEASE

Consider reversible$-$exothermic gasphase $SO3$ production reaction $($SO$2+\frac{1}{2}O2$harrSO$3)$ occuring in a three stage, plug flow reactor system shown below. The reactors operate at adiabatic conditions with interstage cooling in between.

a$)$ Derive adiabatic line equation for the first reactor.

b$)$ Find the exit temperature of the first reactor $($T$1$f$)$ to reach $73\%$ conversion by using the adiabatic line equation and draw the adiabatic line on the given XA$-$T diagram.

c$)$ The exit stream from the first reactor is cooled down to temperature T$20$ such that the rate at the inlet to the second reactor is the same as the rate at the first reactor exit. What is the T$20?$ Show the corresponding points and $c)$ on the given XA$-$T diagram.

$\backslash$table$[[x_A,T,C,-r_A,--\frac{1}{r_A}$