已知：$C\left(s\right)+H_{2}O\left(g\right)=CO\left(g\right)+H_2\left(g\right)$ $△H=aKJ/mol$

$2C\left(s\right)+O_2\left(g\right)=2CO\left(g\right)$        $△H=-220KJ/mol$

$H-H$、$O=O$和$O-H$键的键能分别为436、496和462 $KJ/mol$，则$a$为

－332 －118 ＋350 ＋130