$2/$
$CH4+2O2\overset{t^o}{\rightarrow}CO2+2H2O$
$b/$
$n_{CH4}=3,36/22,4=0,15 mol$
$⇒n_{O2}=0,15x2=0,3 mol$
$V_{O2}=0,3x22,4=6,72 l$
$c/$
$2KClO3\overset{t^o}{\rightarrow}2KCl+3O2$
$0,2 $ → $0,3$
$n_{KClO3}=0,2.122,5=24,5 g$
$3/$
$a/$
$4Al+3O2\overset{t^o}{\rightarrow}2Al2O3$
$b/$
$n_{Al}=2,16/27=0,08 mol$
$⇒n_{O2=0,08x3/4=0,06 mol$
$V_{O2}=0,06.22,4=1,344 l$
$c/$
$2KMnO4\overset{t^o}{\rightarrow}K2MnO4+MnO2+O2$
$0,12$ → $0,06$
$m_{KMnO4}=0,12.158=18,96 g$