VOLTAIC CELL: A SPONTANEOUS ENERGY RELEASING REDOX
REACTION…USING Fe AND Pb
ELECTRONS RELEASED BY
REDUCING AGENT(THAT
WHICH IS OXIDIZED-Fe(s)
NEGATIVE SALT BRIDGE ION
CARRIES NEGATIVE CHARGE
BACT TO ANODE, THIS IS
THE IONIC HALF OF THE
CIRCUIT.
ELECTRONS GAINED BY
OXIDIZING AGENT IONS IN
CATHODAL SOLUTION (Pb+2
(aq) ) THE CATHODE ITSELF IS
Pb SOLID.
ELECTRONS REPELLED
FROM ANODE INTO WIRE,
ELECTRONS CARRY
NEGATIVE CHARGE
THROUGH WIRE , RELEASE
CHEMICAL POTENTIAL
ENERGY AS ELECTRICITY
VOLTAIC
CELL
VOLTMETER
SLIDE ONE
OVERVIEW
ANIMATION
SO4
SO4
2-
2-
Na+
Na+
SO42Na+ Na+
2e-
-
Fe
Fe
2eFe2+
SO42-
Fe0(s)  2e- + Fe2+
ANODE (ANOX)
2+
PbPb Pb
Na+ Na+
Pb2+
Pb
+
+
+
Pb
2e- + Pb2+  Pb0(s)
CATHODE (REDCAT)
ANODE LIST
Fe0(s)  2e- + Fe2+
F0 IS:
1)
2)
3)
4)
5)
6)
OXIDIZED
IS THE ANODE
TOPMOST ON TABLE J.
IS ELECTRON SOURCE
IS REDUCING AGENT
IS COVERTED TO AN AQUIOUS ION.
THE ANODE:
1) IS NEGATIVE DUE TO ELECTRONS BEING PRODUCED.
1) DISSOLVES…LOSES MASS
2) THE ANODAL SOLUTION BECOMES + DUE TO PRODUCTION OF
A POSITIVE ION…SALT BRIDGE – ION NEUTRALIZES.
CATHODE LIST
2e- + Pb2+  Pb0(s)
Pb+2 IS:
1)
2)
3)
4)
5)
6)
REDUCED
REACTS AT CATHODE (Pb 0)
BOTTOM MOST ON TABLE J.
IS ELECTRON DESTINATION
IS OXIDIZING AGENT AGENT
ITS AQUIOUS ION IS SOLIDIFIED.
THE CATHODE:
1) IS POSITIVE DUE TO ELECTRONS BEING CONSUMED.
1) ELECTROPLATED…GAINS MASS
2) THE CATHODAL SOLUTION BECOMES - DUE TO CONSUMPTION
OF A POSITIVE ION…SALT BRIDGE + ION NEUTRALIZES.
ELECTRON FLOW
- ELECTRODES: FROM ANODE (SOLID IRON
Fe) TRANSFERS ELECTRONS TO CATHODE
(SOLID LEAD Pb).
-SPECIES: FROM Fe0 TO Pb+2
THE CIRCUIT
-THE WIRE:THE FLOW OF ELECTRONS FROM
ANODE TO CATHODE IS ELECTRICAL
CONDUCTION, - CHARGE LEAVES ANODE
CARRIED BY ELECTRONS.
-SALT BRIDGE: NEGATIVE CHARGE RETURNS
TO ANODE AS NEGATIVE IONS. NOTE ♪,
ELECTRONS NEVER TRAVEL IN SALT BRIDGE
OR ANY SOLUTION.
VOLTAIC
AS THE Fe(S) IS
CELL
OXIDIZED, IT
DISSOLVES AND
SLIDE TWO
THE ANODE
LOSES MASS AND
THE ANODE
2e- ARE
AS THE Fe(S) IS
OXIDIZED, IT
DISSOLVES AND THE
VOLTMETER
ANODE LOSES MASS,
THE IRON(II) IONS
WILL MAKE THE
ANODE SOLUTION
POSITIVE,
THEREFORE THE
+
Na
NEGATIVE SALT
SO42- Na+
2SO
4
SO42Na+ Na+BRIDGE ION MOVES IN
TO NEGATE THE +
CHARGE
RELEASED
2eFe
Fe
Fe2+
SO4
Fe0(s)  2e- + Fe2+
ANODE (ANOX)
2-
NSBTA
Negative salt bridge to
anode
Pb2+
Never sell booze to
adolescents!
Pb
Pb
2e- + Pb2+  Pb0(s)
CATHODE (REDCAT)
VOLTAIC
CELL
VOLTMETER
SLIDE
THREE
e- FLOW
2eFe
Fe
Fe0(s)  2e- +
ELECTRONS ALWAYS
MOVE FROM Na
ANODE
+
2SOCATHODE
TO
4
Na+
SO42(FATCAT). THE
Na+ Na+
ELECTRONS BUILD UP
IN THE ANODE
Fe2+ MAKING IT NEGATIVE,
TRAVEL TO THE
SO42-CATHODE WHERE A
METAL ION GAINS
Pb2+
THEM IN REDUCTION,
THE CATHODE IS
POSITIVE.
VOLTMETER ALWAYS
Fe2+ POINTS TO CATHODE, 2e +
ANODE (ANOX)
2ePb
Pb
Pb2+  Pb0(s)
CATHODE (REDCAT)
VOLTAIC
CELL
VOLTMETER
SLIDE
FOUR
THE
CATHODE
THE POSITIVE SALT ION
MIGRATES TO THE
CATHODE TO REPLACE +
CHARGE LOST AS Pb(II)
Na+
2SO4 Na+
ARE REDUCED TO2-Pb
SO42SOLID.SO4
Na+ Na+
2eFe
Fe
2eFe2+
SO42AS ELECTRONS ARE
GAINED BY Pb(II) IONS
FROM THE CATHODE,
THE IONS BECOME
REDUCED INTO Pb(S)
Fe0(s)  2e- + Fe2+
ANODE (ANOX)
Pb2+ Pb
Na+ Na+
Pb
Pb2+
Pb
THE SOLID
LEAD
BONDS
(METALLIC
BONDING)
THE
CATHODE
WHICH
GAINS
MASS. THIS
IS
ELECTROPL
ATING.
2e- + Pb2+  Pb0(s)
CATHODE (REDCAT)