1/
$a,4Na+O_2\xrightarrow{t^o} 2Na_2O$
$b,2KMnO_4\xrightarrow{t^o} K_2MnO_4+MnO_2+O_2$
$c,Zn+2HCl\xrightarrow{} ZnCl_2+H_2↑$
$d,K_2O+H_2O\xrightarrow{} 2KOH$
4/
$a,PTPƯ:2H_2+O_2\xrightarrow{t^o} 2H_2O$
$n_{H_2}=\dfrac{11,2}{22,4}=0,5mol.$
$Theo$ $pt:$ $n_{O_2}=\dfrac{1}{2}n_{H_2}=0,25mol.$
$⇒V_{O_2}=0,25.22,4=5,6l.$
$b,Theo$ $pt:$ $n_{H_2O}=n_{H_2}=0,5mol.$
$⇒m_{H_2O}=0,5.18=9g.$
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