Respuesta :
Answer:
a) [tex]E_{cell} = - 0.825 V[/tex]
The electro-chemical cell is non spontaneous because [tex]E_{cell}[/tex] is negative
b) [tex]E_{cell} = 0.733 V[/tex]
The electro-chemical cell is spontaneous because [tex]E_{cell}[/tex] is positive
Explanation:
a)
[tex]Cu^{2+} = 0.14 M\\Fe^{2+} = 0.0040 M\\E_{Cu^{2+} /Cu} ^{0} = 0.339 V\\E_{Fe^{2+} /Fe} ^{0} = -0.440 V[/tex]
Electron change, n = 2
[tex]Cu || Cu^{2+} (0.14 M) || Fe^{2+} (0.0040M) | Fe(s)\\Cu + Fe^{2+} \rightarrow Fe(s) + Cu^{2+} (aq)\\ E_{cell} ^{0} = E_{anode} ^{0} - E_{cathode} ^{0}\\E_{cell} ^{0} = E_{Fe^{2+}/Fe } ^{0} - E_{Cu^{2+}/Cu} ^{0}\\E_{cell} ^{0} = -0.440 - 0.339\\E_{cell} ^{0} = -0.779 V\\E_{cell} = E_{cell} ^{0} - \frac{0.0591}{n} log(\frac{Cu^{2+} }{Fe^{2+} } )\\E_{cell} = -0.779 - \frac{0.0591}{2} log(\frac{0.14}{0.0040 } )\\E_{cell} = - 0.825[/tex]
The electro-chemical cell is non spontaneous because [tex]E_{cell}[/tex] is negative
b)
[tex]Sn^{4+} = 0.11 M\\ Sn^{2+} = 0.0067 M\\Fe^{2+} = 0.0019 M\\Fe^{3+} = 0.15 M\\E_{Sn^{4+} /Sn^{2+}} ^{0} = 0.154 V\\E_{Fe^{3+} /Fe^{2+}} ^{0} = 0.771 V[/tex]
Electron change, n = 2
[tex]Pt || Sn^{2+} (0.0067 M) || Sn^{4+} (0.11 M) | Fe^{3+}(0.15 M)\\Sn^{2+} + 2Fe^{3+} \rightarrow Sn^{4+} + 2Fe^{2+} (aq)\\ E_{cell} ^{0} = E_{anode} ^{0} - E_{cathode} ^{0}\\E_{cell} ^{0} = E_{Fe^{3+}/Fe^{2+} } ^{0} - E_{Sn^{4+}/Sn{2+}} ^{0}\\E_{cell} ^{0} = 0.771 - 0.154\\E_{cell} ^{0} = 0.617 V\\E_{cell} = E_{cell} ^{0} - \frac{0.0591}{n} log(\frac{[Fe^{2+}]^2 [Sn^{4+}]}{[Fe^{3+}]^2 [Sn^{2+}] } )\\E_{cell} = 0.617 - \frac{0.0591}{2} log(\frac{0.0019^2 * 0.11}{0.15^2 * 0.154 } )\\E_{cell} = 0.733 V[/tex]
The electro-chemical cell is spontaneous because [tex]E_{cell}[/tex] is positive
