$C + {O_2} \to C{O_2};\Delta H = - 393\,J$
$2Zn + {O_2} \to 2ZnO;\Delta H = - 412\,J$
$MnO_4^ - \,\, + \,\,{C_2}O_4^{2 - }\,\, + \,\,{H^ + }\, \rightarrow \,\,M{n^{2 + }}\, + \,C{O_2} + \,{H_2}O$