\(2Al+6HCl\to 2AlCl_3+3H_2\\ Fe+2HCl\to FeCl_2+H_2\\ n_{HCl}=0,2.4=0,8(mol)\\ \Rightarrow \begin{cases} 56.n_{Fe}+27.n_{Al}=22\\ 2.n_{Fe}+3.n_{Al}=0,8 \end{cases}\Rightarrow \begin{cases} n_{Fe}=0,39(mol)\\ n_{Al}=0,007(mol) \end{cases}\\ \Rightarrow \begin{cases} \%m_{Fe}=\dfrac{0,39.56}{22}.100\%=99,27\%\\ \%m_{Al}=100\%-99,27\%=0,73\% \end{cases}\)

\(A_{Fe}=N.n_{Fe}=2,5.6.10^{23}=15.10^{23}\) nguyên tử

Lưu Võ Tâm Như láo :')

:v họk trò mằ z là chếc gùi :<

ko tin hay sao mà cơ á 

\(a,PTHH:4P+5O_2\xrightarrow{t^o}2P_2O_5\\ b,n_P=\dfrac{6,2}{31}=0,2(mol)\\ \Rightarrow n_{O_2}=\dfrac{5}{4}n_P=0,25(mol)\\ \Rightarrow V_{O_2(đktc)}=0,25.22,4=5,6(l)\\ c,n_{P_2O_5}=\dfrac{1}{2}n_P=0,1(mol)\\ \Rightarrow m_{P_2O_5}=0,1.142=14,2(g)\)

\(2NaI+Cl_2\to 2NaCl+I_2\)

Đặt \(n_{NaI}=x(mol)\Rightarrow n_{NaCl}=x(mol)\)

\(\Rightarrow m_{dd giảm}=m_{NaI}-m_{NaCl}=150x-58,5x=9,15\\ \Rightarrow x=0,1(mol)\\ \Rightarrow m_{NaI}=0,1.150=15(g)\)