$298 \,K \,NH_3$$_{(g)}$ અને $H_2O_{(l)}$ ની નિર્માણ ઉષ્મા અનુક્રમે $-46.0$ અને $-286.0\, kJ \,mol^{-}$ છે.
$(i)\,\,\Delta H_f^o\,\,of\,{H_2}{O_{(\ell )}}\, = \,\, - 68.3\,K\,\,cal\,\,mo{l^{ - 1}}$
$(ii)\,\,\Delta H_{comb}^o\,\,of\,{C_2}{H_2}\, = \,\, - 337.2\,K\,\,cal\,\,mo{l^{ - 1}}$
$(iii)\,\,\Delta H_{comb}^o\,\,of\,\,{C_2}{H_4}\,\, = \,\, - \,363.7\,\,K\,\,cal\,\,mo{l^{ - 1}} $
$2{C_8}{H_{18}}(g) + 25{O_2}(g) \to 16C{O_2}(g) + 18{H_2}O(g).$
ત્યારે $\Delta H,\,\Delta S$ અને $\Delta G$ની નિશાની .......... હશે.
[આપેલ છે : પાણીની વિશિષ્ટ ઉષ્મા $=4.18\, {~J} \,{~g}^{-1}\, {~K}^{-1},$ પાણીની ઘનતા $=1.00\, {~g}\, {~cm}^{-3}$ ]
(ધારો કે મિશ્રણ પર કોઈ વોલ્યુમ ફેરફાર નથી)
$\frac{1}{2}C{l_2}_{(g)}\,\xrightarrow{{\frac{1}{2}{\Delta _{diss}}{H^\Theta }}}\,Cl_{(g)}\,\,\xrightarrow{{{\Delta _{eg}}{H^\Theta }}}\,\,C{l^ - }_{(g)}\,\xrightarrow{{{\Delta _{hyd}}{H^\Theta }}}\,C{l^ - }_{(aq)}$
$({\mkern 1mu} {\Delta _{diss}}{\mkern 1mu} H_{C{l_2}}^\Theta {\mkern 1mu} = {\mkern 1mu} {\mkern 1mu} 240{\mkern 1mu} {\mkern 1mu} kJ{\mkern 1mu} {\mkern 1mu} mo{l^{ - 1}},{\mkern 1mu} {\mkern 1mu} {\Delta _{eg}}{\mkern 1mu} H_{Cl}^\Theta {\mkern 1mu} = {\mkern 1mu} {\mkern 1mu} - 349{\mkern 1mu} {\mkern 1mu} kJ{\mkern 1mu} {\mkern 1mu} mo{l^{ - 1}},{\mkern 1mu} {\mkern 1mu} $
${\Delta _{hyd}}H_{C{l^ - }}^\Theta {\mkern 1mu} = {\mkern 1mu} {\mkern 1mu} - {\mkern 1mu} 381{\mkern 1mu} kJ{\mkern 1mu} {\mkern 1mu} mo{l^{ - 1}})$