nH2=0.3(mol)
pthh:Mg+2HCl->MgCl2+H2(khí)
MgO+2HCl->MgCl2+H2O
theo pthh:nMg=nH2->nMg=0.3(mol)
mMg=0.3*24=7.2(g) %Mg=7.2:15.2=47%
%MgO=100-47=53%
mMgO=8(g)->nMgO=0.2(mol)
theo pthh1:nHCl=2nMg->nHCl(1)=0.3*2=0.6(mol)
theo pthh2:nHCl=2nMgO->nHCl(2)=0.2*2=0.4(mol)
tổng nHCl=1(mol)
Vdd HCl=1:1.25=0.8(l)=800ml