`#AkaShi`
PTHH:
`Fe_3O_4 + 4H_2 -> 3Fe + 4H_2O (1) `
`PbO + H_2 -> Pb + H_2O (2) `
Gọi `x` là số mol của `Fe_3O_4` ; `y` là số mol của `PbO`
`n_{H_2}=(11,2)/(22,4)=0,5 (mol)`
`n_{H_2}=n_{H_2 (1)}+n_{H_2 (2)}`
`⇒4x+y=0,5 (mol)`
`⇒232x+98y=45,5 (g)`
Ta có hệ pt:
$\left \{ {{4x+y=0,5} \atop {232x+98y=45,5}} \right.$
`⇒x≈0,02 ; y≈0,4125`
`⇒m_{Fe_3O_4}=0,02xx232=4,64 (g)`
`⇒m%_{Fe_3O_4}=(4,64)/(45,5)xx100%≈10,2%`
`⇒m%_{PbO}=100%-10,2%=89,8%`
b) Theo pt:
`n_{Fe}=0,02xx3=0,06 (mol)`
`n_{Pb}=0,0,4125xx1=0,35 (mol)`
`n_{H_2O}=n_{H_2O (1)}+n_{H_2O (2)}=0,02xx4+0,4125=0,08+0,4125=0,4925 (mol)`
`⇒m_{KL}=a=0,06xx56+0,4125xx82=37,185 (g)`
`⇒m_{H_2O}=b=0,4925xx18=8,865 (g)`