The heat evolved on combustion of 1 g of starch, ${\left(C_6{H}_{10}{O}_5\right)}_x$  into  $C{O}_2\left(g\right)$
and $H_{2}O\left(1\right)$  is 4.6 kcal.  Heat of formation of $C{O}_2\left(g\right)$  and $H_{2}O\left(l\right)$  are$-94.2 and -68.4 kcal/mol,$ respectively.  The magnitude of standard enthalpy of formation of    1 g of starch ( in kcal) is