\(n_{Fe}=\dfrac{2.8}{56}=0.05\left(mol\right)\)
\(n_{Cu}=\dfrac{1.6}{64}=0.025\left(mol\right)\)
\(n_{HNO_3}=0.5\cdot0.1=0.05\left(mol\right)\)
\(n_{HCl}=0.5\cdot0.4=0.2\left(mol\right)\)
\(\Rightarrow n_{H^+}=0.05+0.2=0.25\left(mol\right)\)
\(Fe+NO_3^-+4H^+\rightarrow Fe^{3+}+NO+2H_2O\)
\(0.05.....0.05.....0.2......0.05\)
\(\Rightarrow\) Fe và NO3- phản ứng hết
\(Cu+2Fe^{3+}\rightarrow Cu^{2+}+2Fe^{2+}\)
\(0.025....0.05........0.025......0.05\)
\(\Rightarrow\) X gồm : Cu2+ : 0.025 (mol) , Fe2+ : 0.05 (mol) , H+ : 0.05 (mol) , Cl- : 0.2 (mol)
Khi X + AgNO3 :
\(Ag^++Cl^-\rightarrow AgCl\)
\(........0.2.......0.2\)
\(3Fe^{2+}+NO_3^-+4H^+\rightarrow3Fe^{3+}+NO+2H_2O\)
\(0.0375....................0.05\)
\(\Rightarrow n_{Fe^{2+}\left(dư\right)}=0.05-0.0375=0.0125\left(mol\right)\)
\(Fe^{2+}+Ag^+\rightarrow Fe^{3+}+Ag\)
\(0.0125..........................0.0125\)
\(m_{kt}=m_{AgCl}+m_{Ag}=0.2\cdot143.5+0.0125\cdot108=30.05\left(g\right)\)