$(W)\,\, = \,\, - 2.303\,\,nRT\,\log \,\frac{{{P_1}}}{{{P_2}}}\,\,\,$
$ = \,\, - \,2.303\,\, \times \,\,1\,\, \times \,\,2\,\, \times \,\,300\,\, \times \,\,{\log _{10}}\,\frac{{10}}{1}\,\, $
$= \,\, - \,1381.8\,\,calories$
$ C(s)\,\, + \,\,{O_2}(g)\,\, \to \,\,C{O_2}\,(g)$ $\Delta H = \,\, - \,94\,\,kcal$
${H_2}\,(g)\,\, + \,\,\frac{1}{2}\,{O_2}\,(g)\,\, \to \,\,{H_2}O\,(g),$ $\Delta H\,\, = \,\, - \,68\,\,kcal$
${C_2}{H_5}OH\,(\ell )\,\, + \,\,3{O_2}\,(g)\,\, \to \,\,2C{O_2}\,(g)\,\, + \,\,3{H_2}O\,(\ell ),$$\Delta H\,\, = \,\,\, - \,327\,\,kcal$
$C$ $($હીરા$)$ $ + {O_2}(g) \to C{O_2}(g);\,\Delta H = - 393.5$
જો ગ્રેફાઇટથી હીરો બને તો ઉપરના આંકડા પરથી $\Delta H$.......$kJ$