a) Fe2O3 + 6HCl => 2FeCl3 + 3H2O
nFe2O3=8/160=0,05mol
=> nFeCl3=2.0,05=0,1mol
=> mFeCl3=0,1,162,5=16,35g
b) nHCl=6.0,05=0,3mol
Cm=n/v => V=n/Cm=0,3/0,2=1,5l
c) mdd=V.D => mddHCl=1,5.1,05=1,575g
mddspư=moxit + mHCl - mH2O
= 8 + 1,575 =9,575g
=> C%=16,35/9,575 . 100%=170,75%