$14.$ The chemical equation for cellular respiration is:

$($a$)$ C$6$H$12$O$6+602->6$CO$2+6$H$2$O $+$ ATP

$($b$)2$H$2+$ O$2->2$H$2$O

$($c$)$ Zn $+2$HCl $->$ ZnCl$2+$ H$2$

$($d$)$ CaCO$3->$ CaO $+$ CO$2$