Question

Hoa tan 4,5 hop kim nhom va magie trong dung dich H₂SO₄ loang du , thay co 5,04 lit khi hidro bay ra (dktc)

a) Viet phuong trinh hoa hoc

b) Tinh thanh phan phan tram cua cac kim loai co trong hop kim

Answer 1

\(n_{Al}=a\left(mol\right),n_{Mg}=b\left(mol\right)\)

\(m=27a+24b=4.5\left(g\right)\left(1\right)\)

\(n_{H_2}=\dfrac{5.04}{22.4}=0.225\left(mol\right)\)

\(2Al+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2\)

\(Mg+H_2SO_4\rightarrow MgSO_4+H_2\)

\(n_{H_2}=1.5a+b=0.225\left(mol\right)\left(2\right)\)

\(\left(1\right),\left(2\right):a=0.1,b=0.075\)

\(\%Al=\dfrac{0.1\cdot27}{4.5}\cdot100\%=60\%\)

\(\%Mg=40\%\)

Answer 2

Giup minh voi