a) $2Al +3 H_2SO_4 \to Al_2(SO_4)_3 + 3H_2$
b) $n_{Al} = \dfrac{5,4}{27} = 0,2(mol)$
Theo PTHH : $n_{H_2} = \dfrac{3}{2}n_{H_2} = 0,3(mol)$
$V_{H_2} = 0,3.22,4 = 6,72(lít)$
c) $n_{H_2SO_4} = n_{H_2} = 0,3(mol)$
$\Rightarrow m_{dd\ H_2SO_4} = \dfrac{0,3.98}{19,6\%} = 150(gam)$
$\Rightarrow m_{dd\ sau\ pư} = 5,4 + 150 - 0,3.2 = 154,8(gam)$
$C\%_{Al_2(SO_4)_3} = \dfrac{0,1.342}{154,8}.100\% = 22,09\%$
\(n_{Al}=\dfrac{5,4}{27}=0,2(mol)\\ a,PTHH:2Al+3H_2SO_4\to Al_2(SO_4)_3+3H_2\\ b,n_{H_2}=1,5.n_{Al}=0,3(mol)\\ \Rightarrow V_{H_2}=0,3.22,4=6,72(l)\\ c,n_{H_2SO_4}=n_{H_2}=0,3(mol)\\ \Rightarrow m_{dd_{H_2SO_4}}=\dfrac{0,3.98}{19,6\%}=150(g)\\ n_{Al_2(SO_4)_3}=0,5.n_{Al}=0,1(mol)\\ \Rightarrow C\%_{Al_2(SO_4)_3}=\dfrac{0,1.342}{5,4+150-0,3.2}.100\%=22,09\%\)
\(n_{Al}=\dfrac{5,4}{27}=0,2\left(mol\right)\\ a,2Al+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2\\ b,n_{H_2}=n_{H_2SO_4}=\dfrac{3}{2}.0,2=0,3\left(mol\right)\\ b,V_{H_2\left(\text{đ}ktc\right)}=0,3.22,4=6,72\left(l\right)\\ c,n_{\text{dd}Al_2\left(SO_4\right)_3}=\dfrac{1}{2}.0,2=0,1\left(mol\right)\\ m_{\text{dd}H_2SO_4}=\dfrac{0,3.98}{19,6\%}=150\left(g\right)\\ m_{\text{dd}sau}=5,4+150-0,3.2=154,8\left(g\right)\\ C\%_{\text{dd}muoi}=\dfrac{342.0,1}{154,8}.100\approx22,093\%\)
