PTHH:MnO2 + 4HCl -> MnCl2 + Cl2 + 2H2O
Ta có:
nCl2 lt = nMnO2 = 21,75/(55+16.2)=0,25 mol
=> nCl2=0,25.80%=0,2 mol
=> VCl2=0,2.22,4=4,48 lít
PTHH: 2Fe + 3Cl2 -> 2FeCl3
=> nFeCl3 = 2/3nCl2 = 0,4/3 mol
=> mFeCl3 = 0,4/3.(56+35,5.3) = 21,67 gam
M + Cl2 -> MCl2
=> nM = nCl2 = 0,2 mol
=> MM = 4,8/0,2 = 24
Vậy M là Mg