`#AkaShi`
PTHH: `Fe_3O_4+8HCl \to FeCl_2+2FeCl_3+4H_2O`
`n_{Fe_3O_4}=(53,36)/232=0,23 (mol)`
`⇒n_{HCl}=(0,23xx8)/1=1,84 (mol)`
`⇒m_{HCl pư}=1,84xx36,5=67,16 (g)`
`⇒m_{dd HCl}=(67,16):7,3%=920 (g)`
b) `n_{FeCl_2}=n_{Fe_3O_4}=0,23 (mol)`
`⇒n_{FeCl_3}=(0,23xx2)/1=0,46 (mol)`
`⇒n_{FeCl_2}=0,23xx127=29,21 (g)`
`⇒n_{FeCl_3}=0,46xx162,5=74,75 (g0`
`⇒m_{dd sau pư}=920+53,36=973,36 (g)`
`⇒C%_{FeCl_2}=(29,21)/(973,36)xx100%≈3%`
`⇒C%_{FeCl_3}=(74,75)/(973,36)xx100%≈7,68%`