(Given ${\Delta _{fus}}H = 6\, kJ\, mol^{-1}$ at $0\,^oC$,
$C_p(H_2O, l) =75.3\, J\, mol^{-1} \, K^{-1}$ ,
$C_p(H_2O, s) = 36.8\, J\, mol^{-1} \, K^{ -1}$ )
$(a)$ Energy change of $1\,mol$, $H_2O\,(l)$, at $5\,^oC$
$\to \,1\,mol$, $H_2O\,(l)$ , $0\,^oC$
$(b)$ Energy change of $1\,mol$, $H_2O\,(l)$, at $0\,^oC$
$\to \,1\,mol$, $H_2O\,(s)$ (ice) , $0\,^oC$
$(c)$ Energy change of $1\,mol$, Ice $(s)$, at $0\,^oC$
$\to \,1\,mol$, Ice $(s)$ , $-5\,^oC$
Total $\Delta H$
$ = \,{C_P}\,[{H_2}O\,(l)]\,\,\Delta T\,\, + \,\Delta H$ freezing $ + \,\,{C_P}\,[{H_2}O\,(s)]\,\,\Delta T$
$ = \,(75.3\,\,J\,\,mo{l^{ - 1}}\,{K^{ - 1}})\,( - 5)\,K\, + ( - \,6\, \times \,{10^3}\,\,J\,mo{l^{ - 1}}\,{K^{ - 1}})$ $+ \,(36.8\,\,J\,mo{l^{ - 1}}\,{K^{ - 1}})\,( - 5)\,K$
$\Delta H\,\, = \,\, - \,6.56\,\,kJ\,mo{l^{ - 1}}$ (exothermic process)
So, $\Delta H\,\, = \,\,6.56\,\,kJ\,mo{l^{ - 1}}$
કિલોજૂલ અને $C + O_2$ $\rightarrow$ $CO_2$ :$\Delta H = x$ કિલોજૂલ, તો $x$ ..... કિલોજૂલ થાય.
$2 \mathrm{Fe}_{(\mathrm{s})}+\frac{3}{2} \mathrm{O}_{2(\mathrm{~g})} \rightarrow \mathrm{Fe}_2 \mathrm{O}_{3(\mathrm{~s})}, \Delta \mathrm{H}^{\mathrm{o}}=-822 \mathrm{~kJ} / \mathrm{mol}$
$\mathrm{C}_{(\mathrm{s})}+\frac{1}{2} \mathrm{O}_{2(\mathrm{~g})} \rightarrow \mathrm{CO}_{(\mathrm{g})}, \Delta \mathrm{H}^{\mathrm{o}}=-110 \mathrm{~kJ} / \mathrm{mol}$
$3\mathrm{C}_{(\mathrm{s})}+\mathrm{Fe}_2 \mathrm{O}_{3(\mathrm{~s})} \rightarrow 2 \mathrm{Fe}_{(\mathrm{s})}+3 \mathrm{CO}_{(\mathrm{g})}$ આપેલા પ્ર્ક્રિયા માટે એન્થાલ્પી ફેરફાર__ _ _$J/mol$ છે.
$\left[\right.$ ઉપયોગ $: {H}^{+}({aq})+{OH}^{-}({aq}) \rightarrow {H}_{2} {O}: \Delta_{{\gamma}} {H}=-57.1\, {k} {J} \,{mol}^{-1},$
વિશિષ્ટ ઊર્જા ${H}_{2} {O}=4.18 {Jk}^{-} {g}^{-},$
ઘનતા ${H}_{2} {O}=1.0\, {~g} {~cm}^{-3},$
મિશ્રણ પર દ્રાવણના કદમાં કોઈ ફેરફાર થતો નથી એમ ધારો.]
લિસ્ટ $I$ (સમીકરણો) |
લિસ્ટ $II$ (પ્રક્રમનો પ્રકાર) |
$A. \,\,K_p > Q$ | $(i)$ બિન સ્વયંભૂ |
$B.\,\,\Delta G^o < RT ln Q$ | $(ii)$ સંતુલન |
$C.\,\,K_p = Q$ | $(iii)$ સ્વયંભૂ અને ઉષ્માશોષક |
$D.\,\,T>\frac{{\Delta H}}{{\Delta S}}$ | $(iv)$ સ્વયંભૂ |