Đáp án:
1/
Mg + 2HCl --> MgCl2 + H2
x x
Fe + 2HCl --> FeCl2 + H2
y y
nH2=$\frac{0,56}{22,4}$=0,025
24x+56y=1,04
x+y=0,025
$\left \{ {{x=0,01125} \atop {y=0,01375}} \right.$
%mFe=$\frac{0,01125.56}{1,04}$ .100=60,57%
2/
nH2=$\frac{0,672}{22,4}$ =0,03
3nAl=2nH2
<=>nAl=0,02
%mAl=$\frac{0,02.27}{1,62}$ .100=33,33%
3/
nH2=$\frac{1,008}{22,4}$ =0,045
3nAl=2nH2
<=>nAl=0,03
%mAl=$\frac{0,03.27}{10,41}$ .100=7,78%