a) Fe+2HCl--->FeCl2+H2
n H2=6,72/22,4=0,3(mol)
Theo pthh
n Fe=n H2=0,3(mol
m Fe=0,3.56=16,8(g)
%m Fe=16,8/20.100=84%
%m Ag=100%-84%=16%
b)n HCl=2n H2=0,6(mol)
m HCl=0,6.36,5=21,9(g)
m muối=m Fe+m HCl-m H2
=16,8+21,9-0,6=38,1(g)
V HCl=0,6/2=0,3(l)