$\Delta {U_{BC}} = - 5\,kJ\,mo{l^{ - 1}},{q_{AB}} = 2\,kJ\,mo{l^{ - 1}}$
$\Delta {W_{AB}} = - 5\,kJ\,mo{l^{ - 1}},{W_{CA}} = 3\,kJ\,mo{l^{ - 1}}$
$CA$ પ્રક્રમ દરમિયાન પ્રણાલી દ્વારા શોષાતી ઉષ્મા ......$kJ\,mo{l^{ - 1}}$
$\Delta {U_{BC}} = - 5\,kJ/mol$
For cyclic procrss, $\Delta U=0$
$\Delta {U_{AB}} + \Delta {U_{BC}} + \Delta {U_{CA}} = 0$
$\Delta {U_{CA}} = - \Delta {U_{AB}} - \Delta {U_{BC}}$
$\Delta {U_{CA}} = - ( - 3) - ( - 5) = 8\,kJ/mol$
$\Delta {U_{CA}} = {q_{CA}} + {W_{CA}}$
$8 = {q_{CA}} + 3$
${q_{CA}} = + 5\,kJ/mol$
Heat absorbed has positive sign.
${S_R} + {O_{2\left( g \right)}} \to S{O_{2\left( g \right)}};\,\Delta H = - 296.90\,kJ$
${S_M} + {O_{2\left( g \right)}} \to S{O_{2\left( g \right)}};\,\Delta H = - 299.40\,kJ$
$2C_8H_{18}$ $_{(g)}$ + $25O_2$ $_{(g)}$ $\rightarrow$ $16CO_2$$_{(g)}$ + $18H_2O$ $_{(g)}$