${H_2}O(g) + C(s) \to CO(g) + {H_2}(g);\,\Delta H = 131\,kJ$$CO(g) + \frac{1}{2}{O_2}(g) \to C{O_2}(g);\Delta H = - 282\,kJ$
${H_2}(g) + \frac{1}{2}{O_2}(g) \to {H_2}O(g);\,\Delta H = - 242\,kJ$
$C(s) + {O_2}(g) \to C{O_2}(g);\,\Delta H = X\,kJ$
$X$ નું મૂલ્ય ......$kJ$
$(i)$ $H_{(aq)}^+ + OH^-= H_2O_{(l)} ,$ $\Delta H = -X_1\,kJ \,mol^{-1}$
$(ii)$ $H_{2(g)} + \frac{1}{2}O_{2(g)} = H_2O_{(l)},$ $\Delta H = -X_2\,kJ \,mol^{-1}$
$(iii)$ $CO_{2(g)} + H_{2(g)} = CO_{(g)} + H_2O_{(l)},$ $\Delta H = -X_3\, kJ\, mol^{-1}$
$(iv)$ $ C_2H_{2(g)}+ \frac{5}{2} O_{2(g)} = 2CO_{2(g)} + H_2O_{(l)},$ $\Delta H = -X_4\,kJ \,mol^{-1}$
તો $H_2O_{(l)}$ સર્જનઉષ્મા કેટલી હશે ?
$\frac{1}{2}C{l_2}_{(g)}\,\xrightarrow{{\frac{1}{2}{\Delta _{diss}}{H^\Theta }}}\,Cl_{(g)}\,\,\xrightarrow{{{\Delta _{eg}}{H^\Theta }}}\,\,C{l^ - }_{(g)}\,\xrightarrow{{{\Delta _{hyd}}{H^\Theta }}}\,C{l^ - }_{(aq)}$
$({\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} $
${\Delta _{hyd}}H_{C{l^ - }}^\Theta {\mkern 1mu} = {\mkern 1mu} {\mkern 1mu} - {\mkern 1mu} 381{\mkern 1mu} kJ{\mkern 1mu} {\mkern 1mu} mo{l^{ - 1}})$