$a/$
$4Al+3O2→2Al2O3$
$a/$
$nAl=5,4/27=0,2mol$
$theo$ $pt :$
$nAl2O3=1/2nAl=0,1mol$
$⇒mAl2O3=0,1.102=10,2g$
$c/$
$theo$ $pt :$
$nO2=3/4nAl=3/4.0,2=0,15mol$
$⇒V_{O_{2}}=0,15.22,4=3,36l$
$⇒V_{kk}=5.V_{O_{2}}=5,3,36=16,8l$
$d/$
$pthh :$
$2KMnO4 → K2MnO4 + MnO2 + O2$
$theo$ $pt :$
$nKMnO4=2nO2=2.0,15=0,3mol$
$⇒mKMnO4=0,3.158=47,4g$