дано
m(Al)=540 mg=0.54 g
w(прим)=4%
HCL
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n(AlCL3)-?
V(H2)-?
m(чист Al)=0.54-(0.54*4%/100%)=0.5184 g
0.5184 X
2Al + 6HCl = 2AlCl3 + 3H2
2mol 3mol
M(Al)=27 g/mol , Vm=22.4 L/mol
n(Al)=m/M=0.5184/27=0.0192 mol
n(Al)=n(AlCL3)=0.0192 mol
n(AlCL3)=0.0192 mol
0.5184/2 = X/3
X=0.7776 л - водорода
ответ 0.0192 моль - AlCL3 , 0.7776 л - водорода