$\backslash$table$[[NaAl{S}_{i3}{O}_8(s)>NaAlS{i}_2{O}_6(s)+Si{O}_2(s)$

What would be favored phase assemblage at the following P$-$T cobditons:

$18$kb$,600$ K$?5$ kbar, $800$ K$?5\mathrm{.}2$ kbar, $298$ K

calculate the enthalpy $($H$)$ and entropy $($S$)$ of albite at $700$ K$.$ using the following standard state values and polynomial for isobaric heat capacity:

S$0$ at $298$ K is $221\mathrm{.}8$ J$/$mole K$.$

$\backslash$Delta fH$0=-3929\mathrm{.}86$ kJ$/$mol

Cp $=393\mathrm{.}642415\mathrm{.}5/$T$0\mathrm{.}57\mathrm{.}8928$x$106/$T$2+1\mathrm{.}07064$x$109/$T$3$

Do it the hard way by assuming that heat capacity does increase with temperature.