$1)$ Phosphine can be decomposed at $1\mathrm{.}0$ atm. pressure according to the equation

$4$PH$3->$P$4+6$H$2$

The reaction takes place in a tubular reactor in which $80\%$ of the phosphine feed is

converted. If pure phosphine is fed to the reactor at $680$oC and a rate of $2\mathrm{.}5$ kmol h$-1$

evaluate

a$)$ the heat load on the reactor assuming isothermal operation

b$)$ the gas exit temperature assuming adiabatic operation

Data Enthalpy of reaction $=23\mathrm{.}71$ kJ mol$-1$ phosphine converted at $298$ K

Mean specific heat capacities between $298$K and $1000$ in J mol$-1$ K

$-1$

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