Galvanic Cells
Chapter Name : Electrochemistry |
Sub Topic Code : 102_12_03_03_02 |
Topic Name : Galvanic Cells |
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Sub Topic Name : Measurement Of Electrode Potential |
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Introduction
• Electrode potential of a single half cell cannot be measured. We can only measure the potential difference across 2 half cells. • To measure the standard electrode potential of any metal, standard hydrogen electrode is used as it has an arbitrary potential value = 0 V. • Metals with positive standard potential reduce easily and thus are strong oxidizing agents while metals with negative standard potential do not reduce easily and are strong reducing agents. . .
Pre-Requisites:
• Redox reactions • Galvanic cells
Activity:
Electrical batteries.
Real Life Question:
How the standard electrode is potential measured?
Key Words / FlashCards
| Key Words | Definitions (pref. in our own words) |
|---|---|
| Electrochemical or galvanic cell | A device in which chemical energy released during a chemical reaction is converted into electrical energy. |
| Electrodes | Metallic rods dipped in the electrolyte solution. |
| Anode | It is a positively charged electrode, where electrons are released or oxidation occurs. |
| Cathode | It is a negatively charged electrode, where electrons are accepted or reduction occurs. |
| Half cells | The two containers involving oxidation and reduction half reactions are called Half cells. |
| Electrode potential | The potential difference between the metal rod and its ion in solution due to difference in charge. |
| Cell potential | The potential difference between the two electrodes of a galvanic cell. |
| Standard electrode potential | If the electrode is suspended in a solution of 1 molar concentration at 298 K, the electrode potential is called as standard electrode potential. |
Learning aids / Gadgets
| Gadgets | How it can be used |
|---|---|
| Ncert book | Read table 3.1, which gives the standard electrode potential of different metal species. |
Real life uses :
• As dry cells, mercury cells, rechargeable Ni-Cd batteries, and lead storage cells. • Electrochemical cells are also used to measure pH of solution and solubilities.
Places to visit :
Home.
Practical examples around us
| Examples | Explainations |
|---|---|
| Home | Electrical batteries used in torches, watches are made of electrochemical cells. |
What you learn in Theory:
Measurement of standard electrode potential of a cell.
What you learn in Practice:
How standard electrode potential of metal specie affects its reducing/oxidizing power.