${H_2}C = C{H_2}(g) + {H_2}(g) \to {H_3}C - C{H_3}(g)$
$435 \times 1\,\,\, = \,\mathop {435}\limits_{\overline {\underline {2706} } } $
$\Delta H = 2706 - 2831 = - 125\,kJ$
(નજીકનો પૂર્ણાક) આપેલ : $R =8.3\,J\,K ^{-1}\,mol ^{-1}$
$(i)$ $H_{(aq)}^+ + OH^-= H_2O_{(l)} ,$ $\Delta H = -X_1\,kJ \,mol^{-1}$
$(ii)$ $H_{2(g)} + \frac{1}{2}O_{2(g)} = H_2O_{(l)},$ $\Delta H = -X_2\,kJ \,mol^{-1}$
$(iii)$ $CO_{2(g)} + H_{2(g)} = CO_{(g)} + H_2O_{(l)},$ $\Delta H = -X_3\, kJ\, mol^{-1}$
$(iv)$ $ 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 ?
$H _{2}+\frac{1}{2} O _{2} \rightarrow H _{2} O , \cdots \cdots( ii )$ $\Delta H =-\,287.3 \,kJ\,mol ^{-1}$
$2 CO _{2}+3 H _{2} O \rightarrow C _{2} H _{5} OH +3 O _{2} \cdots \cdots ( iii )$; $ \Delta H =1366.8 \,kJ\,mol ^{-1}$
$C _{2} H _{5} OH (1)$ માટે ની રચનાની પ્રમાણિત એન્થાલ્પી શોધો