Какой класс?вроде 7-9,да ))))))))))
N = n*N(a)
N(a) = 6.02*10^23
n = V/Vм
Vм = 22.4 л
n = 4.48/22.4 = 0.2 моль
N = 0.2*6.02*10^23 = 1.204*10^23
m<span>Fe3O4= 1000*0,72=720кг </span>
<span>n(<span>Fe3O4)720/232=3.1моль</span></span>
<span><span><span>3Fe3O4 +8Al=4Al2O3+9Fe</span></span></span>
<span><span><span>по уравнению реакции пFe=3т(<span>Fe3O4)=3*3,1=9,3моль</span></span></span></span>
<span><span><span><span>m(Fe)9.3*56=520.8г</span></span></span></span>
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