Question

A liquid of volume of $100L$ and at the external pressure of $10atm-Lt$ the liquid is confined inside an adiabatic bath. External pressure of the liquid is suddenly increased to $100atm$ and the liquid gets compressed by $1L$ against this pressure then find,
(i) work (ii) $△U$ (iii) $△H$.

Answer 1

Given: Adiabatic process

$V_1=100$l $P_1=10$atm

$V_2=100-1$ $P_2=100$atm

$=99$l

(i) for adiabatic

work done$=-P_{ext}\left(\Delta V\right)$

$=-P_{ext}(V_2-V_1)$

$=-100$ atm $\times (99-100)l$

$=+100$ atm$-$lit

$W=100$ lit atm

(ii) $\Delta U$, for adiabatic process $\Delta q=0$

$\therefore \Delta U=\Delta Q+W$

$\Delta u=w.=100$ lit atm

(iii) $\Delta H=\Delta U+(P_2{V}_2-P_1{V}_1)$

$=100+(100\times 99-10\times 100)$

$=100+(9900-1000)$

$\Delta H=9000$ atm lit.