$T_t = 1000 K.$ $T_2 = 100\,K$
$m = 32\,g$
$\Delta S = ?$
at constant pressure
$\Delta S = {C_p}\,\ln \,\frac{{{T_2}}}{{{T_1}}}$
$ = 2.303 \times {C_p}\,\log \,\frac{{{T_2}}}{{{T_1}}}$
$ = 2.303 \times 10\,\log \,\frac{{100}}{{1000}}$
$ = - 23.03\,cal\,{\deg ^{ - 1}}$
$H_{2(g)} + \frac{1}{2} O_{2(g)} → H_2O{(l)} + 68.3\,K\,cal$
$CH_{4(g)} + 2O_{2(g)} → CO_{2(g)} + 2H_2O_{(l)} + 210.8\,K\,cal$
તો $K\,cal$ સ્વરૂપમાં મિથેનની નિર્માણ ઉષ્મા શોધો.