Answer :
Answer:
For 1: The largest positive cell potential is of cell having 1st and 4th half reactions.
For 2: The standard electrode potential of the cell is 1.539 V
For 3: The smallest positive cell potential is of cell having 3rd and 4th half reactions. The standard electrode potential of the cell is 0.46 V
Explanation:
The substance having highest positive [tex]E^o[/tex] potential will always get reduced and will undergo reduction reaction.
We are given:
[tex]Ag^++(aq.)+e^-\rightarrow Ag(s);E^o_{Ag^+/Ag}=0.799V\\\\Cu^{2+}+(aq.)+2e^-\rightarrow Cu(s);E^o_{Cu^{2+}/Cu}=0.337V\\\\Ni^{2+}(aq.)+2e^-\rightarrow Ni(s);E^o_{Ni^{2+}/Ni}=-0.28V\\\\Cr^{3+}(aq.)+3e^-\rightarrow Cr(s);E^o_{Cr^{3+}/Cr}=-0.74V[/tex]
Substance getting oxidized always act as anode and the one getting reduced always act as cathode.
To calculate the [tex]E^o_{cell}[/tex] of the reaction, we use the equation:
[tex]E^o_{cell}=E^o_{cathode}-E^o_{anode}[/tex]
- Cell having 1st and 2nd half reactions:
Silver has higher electrode potential. So, this will undergo reduction reaction and act as anode. Copper will undergo oxidation reaction and act as cathode.
[tex]E^o_{cell}=0.799-0.337=0.462V[/tex]
- Cell having 1st and 3rd half reactions:
Silver has higher electrode potential. So, this will undergo reduction reaction and act as anode. Nickel will undergo oxidation reaction and act as cathode.
[tex]E^o_{cell}=0.799-(-0.28)=1.079V[/tex]
- Cell having 1st and 4th half reactions:
Silver has higher electrode potential. So, this will undergo reduction reaction and act as anode. Chromium will undergo oxidation reaction and act as cathode.
[tex]E^o_{cell}=0.799-(-0.74)=1.539V[/tex]
- Cell having 2nd and 3rd half reactions:
Copper has higher electrode potential. So, this will undergo reduction reaction and act as anode. Nickel will undergo oxidation reaction and act as cathode.
[tex]E^o_{cell}=0.337-(-0.28)=0.617V[/tex]
- Cell having 3rd and 4th half reactions:
Nickel has higher electrode potential. So, this will undergo reduction reaction and act as anode. Chromium will undergo oxidation reaction and act as cathode.
[tex]E^o_{cell}=-0.28-(-0.74)=0.46V[/tex]
Hence,
For 1: The largest positive cell potential is of cell having 1st and 4th half reactions.
For 2: The standard electrode potential of the cell is 1.539 V
For 3: The smallest positive cell potential is of cell having 3rd and 4th half reactions. The standard electrode potential of the cell is 0.46 V