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Office XP
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Ken Rogers

2. Voltaic
Cells
Ken Rogers
Miami Killian

3. ? 1M ZnSO4 1M CuSO4 salt bridge voltmeter 2 possible rxns here
Na+ Cu
Cl-
porous plugs
Zn+2
SO4-2
Cu+2

4. reduction reduction Zn+2 + 2e- a Zn -0.76V Cu+2 + 2e- a Cu +0.34V
Zn a Zn+2 + 2e-
-0.34V
Cu a Cu+2 + 2e-
oxidation Zn Cu
porous plugs
SO4-2
Zn+2
SO4-2
Cu+2

5. Oxidation occurs at the Anode Reduction occurs at the Cathode
Zn a Zn+2 + 2e-
+0.76V
Cu+2 + 2e- a Cu
reduction
+0.34V
Cu+2 + Zn a Cu + Zn+2
1.10V
Oxidation occurs at the Anode
Reduction occurs at the Cathode

6. Direction of electron flow?
1.10V
oxidation
reduction _ +
Anode
Cathode Zn Cu Cu e- e-
SO4-2
Zn+2
SO4-2
Zn+2
Cu+2

7. What’s the reaction with the highest potential?
To calculate the voltage, you need to figure out the two half reactions.
What’s the reaction with the highest potential? ?
voltmeter Ag Al
Ag+1
Al+3
NO3-1
NO3-1
NO3-1
NO3-1
1M AgNO3
1M Al(NO3)3

8. ? reduction Ag+1 + e-1 a Ag 0.80 V Al+3 + 3e-1 a Al -1.66 V -0.80 V
Ag a Ag e-1
1.66 V
Al a Al e-1
oxidation
voltmeter Ag Al
Ag+1
Al+3
NO3-1
NO3-1
NO3-1
NO3-1
1M AgNO3
1M Al(NO3)3

9. Voltage is not multiplied by 3.
3 ( )
Ag+1 + e- a Ag
0.80 V
Voltage is not multiplied by 3.
Voltage, like density is an intensive property.
1.66 V
Al a Al e-

10. 3Ag+1 + 3e- a 3Ag
0.80 V
1.66 V
Al a Al e-
3Ag+1 + Al a 3Ag + Al+3
2.46 V

11. Direction of electron flow? Where are the electrons being produced?
2.46 V
Ag+1 + e-1 a Ag
Al a Al e-1 Ag Al
Ag+1 Al
Al+3
NO3-1 Ag e- e- e- Ag
Ag+1 Ag
NO3-1
Ag+1
NO3-1
Al+3
NO3-1
1M AgNO3
1M Al(NO3)3

12. Oxidation occurs at the Anode Reduction occurs at the Cathode

13. Identify the anode and cathode.
2.46 V
Al a Al e-1
Ag+1 + e-1 a Ag
reduction
oxidation
Cathode
Anode

14. Direction of ion flow in salt bridge?
2.46 V
Na+
NO3-1
Cathode
Anode

15. 2.46 V Ag+1 + e-1 a Ag Al a Al+3 + 3e-1 Ag Al Ag+1 Al Al+3 NO3-1 Ag Ag
Na+
NO3-1 Ag Al
Ag+1 Al
Al+3
NO3-1 Ag e- e- e- Ag
Ag+1 Ag
NO3-1
Ag+1
neutral
Al+3
neutral
NO3-1
NO3-1
NO3-1
NO3-1
1M AgNO3
1M Al(NO3)3

16. Anions flow towards the Anode Cations flow towards the Cathode

17. Direction of ion flow in salt bridge?
2.46 V
Na+
NO3-1
Cathode
Anode
Al+3
NO3-1

18. Anode is the negative electrode Cathode is the positive electrode

19. 2.46 V _ +
Cathode
Anode

20. So, what’s this?
NaCl +
Assault and battery