Đáp án:
Giải thích các bước giải:
$3/$
$a,PTPƯ:4P+5O_2\overset{t^o}\to$ $2P_2O_5$
$n_{P}=\dfrac{18,6}{31}=0,6mol.$
$Theo$ $pt:$ $n_{O_2}=\dfrac{5}{4}n_{P}=0,75mol.$
$⇒V_{O_2}=0,75.22,4=16,8l.$
$Theo$ $pt:$ $n_{P_2O_5}=\dfrac{1}{2}n_{P}=0,3mol.$
$⇒m_{P_2O_5}=0,3.142=42,6g.$
$b,V_{kk}=V_{O_2}.5=16,8.5=84l.$
$4/$
$a,PTPƯ:2H_2+O_2\overset{t^o}\to$ $2H_2O$
$n_{H_2}=\dfrac{11,2}{22,4}=0,5mol.$
$Theo$ $pt:$ $n_{H_2O]=n_{H_2}=0,5mol.$
$⇒m_{H_2O}=0,5.18=9g.$
$Theo$ $pt:$ $n_{O_2}=\dfrac{1}{2}n_{H_2}=0,25mol.$
$b,PTPƯ:2KMnO_4\overset{t^o}\to$ $K_2MnO_4+MnO_2+O_2$
$Theo$ $pt:$ $n_{KMnO_4}=2n_{O_2}=0,5mol.$
$⇒m_{KMnO_4}=0,5.158=79g.$
chúc bạn học tốt!
