electrochemical cells and their structure

1. Chemical Society, St John’s College Agra
ELECTRO-CHEMISTRY
Presentation by-
Saurav K Rawat (CHEMSO
President)

2. Electrochemistry
Electrochemical
Cells

3. Electrochemical cells are Batteries

4. Alkaline Batteries
KOH

5. Car Batteries
Pb-Acid H2SO4

6. Mitsubishi iMiEV - Pure Electric Car
$ 36,000 US
$ 50,000 Can
Powered by a 330 v Li-Ion Rechargeable battery
Plugs into your house and takes 14 hours to charge -100 km for $ 0.60
Top Speed 130 km/h 63 hp and 133 lb.-ft. of torque

7. Cell Phone batteries
Lithium Ion Rechargeable battery

8. Lithium Coin Cell

9. Space Ship Batteries
Powered by Radioisotopes

10. Ni-Metal Hydride

11. Notes on Electrochemical Cells
An electrochemical cell – a system of electrodes,
electrolytes, and salt bridge that allow oxidation and
reduction reactions to occur and electrons to flow through an
external circuit.
1. Spontaneous redox reaction
2. Produces electricity from chemicals
3. Is commonly called a battery
The salt bridge allows ions to migrate from one half-cell to
the other without allowing the solutions to mix.

12. Analyzing Electrochemical Cells
The reaction that is higher on the reduction chart is the
reduction and the lower is oxidation and is written in
reverse.

13. For any cell
Oxidation always occurs at the anode and reduction at the
cathode
Electrons flow through the wire and go from anode to
cathode
Anions (- ions) migrate to the anode and cations (+ions)
migrate towards the cathode usually through the salt bridge

14. 1. Draw and completely analyze a Cu/Sn electrochemical cell.
voltmeter
Higher
Greatest Electron Affinity
Reduction
Cathode
Cu2+ + 2e- → Cu(s)
0.34 v
Gains mass
+
e- e-
Cu
Sn
Cu2+
NO3
-
Sn2+
Na-+ -
NO3
NO3
-
0.48 v
Lower
Oxidation
Anode
Sn(s) → Sn2+ + 2e-
+0.14 v
Loses mass
-
Overall Reaction: Cu2+ + Sn → Sn2+ + Cu(s) 0.48 v

15. The Hydrogen half cell involves a gas and requires an inert or nonreactive Pt
electrode.
H2(g) in
Wire to circuit
Pt(s)
H+
Cl-
1 M HCl

16. Draw a H2/Ag electrochemical cell with a KNO3 salt bridge.
2e- voltmeter
0 0.8.800 v v
1.0 M KNO3
H Ag 2
2e-
H+
Cl-
Ag+
NO3
-
NO3
- K+
2Ag+ + H2 → 2Ag + 2H+ 0.80 v
Higher
Greater electron affinity
Reduction
Cathode
+
Ag+ + 1e- → Ag(s)
+0.80 v
Gains mass
oxidation
Anode
-
H2 → 2H+ + 2e-
0.00 v
pH decreases
1 M HCl 1 M AgNO3
Pt

17. Rawat’s Creation-rwtdgreat@
gmail.com
rwtdgreat@yahoo.co.uk
RawatDAgreatt/LinkedIn
www.slideshare.net/
RawatDAgreatt
Google+/blogger/Facebook
/
Twitter-@RawatDAgreatt
+919808050301