🔹 Electrochemistry : A branch of science that explores the connection between electrical current and chemical reactions, linking them together.

- Looking ahead, 🧪Electrochemical cells are classified into two main types:

🌿🔋Electrolytic cells & ⚗️Galvanic cells.

🔋 Electrolytic Cell 🔋

🔋 Electrolytic cell :

- Electrolytic cell is a device which converts :
⚡️Electrical energy(from an external source) ➡️➡️🔋Chemical energy.

- An electrolytic cell contains 2 rods, also called electrodes⚗️.
🌿These electrodes can be made of different metals or the same metal, like graphite or metallic ones. They are dipped in the same 🔬electrolytic solution.

- The electrode is linked to the battery🔋.
🌿One electrode connected to the positive terminal of the battery is called the Anode (+), marked with a positive sign.
🌿The other electrode connected to the negative terminal of the battery is known as the Cathode (-), bearing a negative sign. ⚡️🔋

⚗️ Galvanic cell ⚗️

⚗️ Galvanic cell :

- Galvanic cell is a device which converts :
🔋Chemical energy(of a redox reaction) ➡️➡️⚡Electrical energy.

- An Galvanic cell contains 2 rods, also called electrodes⚗️.
🌿These electrodes(half cells) are made of different metals and are connected by salt bridge. They are dipped in different electrolytic solution respective 🔬electrolytic solution.

- The electrodes are connected to a potentiometer or voltmeter by an electrical wire. ⚡️

- The electrode where oxidation occurs is called :
🌿Anode (Negative (-) Electrode). ⚗️

- The electrode where reduction occurs is called : also spontaneous redox reaction takes place on electrode
🌿Cathode (Positive (+) Electrode). ⚡️

🌿Example: Daniel cell 🔄

🌊Salt bridge & ⚖️Functions :

🌿 A salt bridge is like an upside-down U-tube filled with a strong electrolyte solution, such as
💡KCl, KNO3, or NH4Cl.
🌿These electrolytes are chosen because the ions move at similar speeds, helping balance charges.

⚖️Function of the Salt Bridge:

🌿Connects🔗 Half-Cells : Joins them to complete the circuit.
🌿Prevents Mixing🚫 : Stops solution movement between half-cells.
🌿Maintains Balance⚖️ : Keeps both halves electrically neutral.
🌿Prevents Potential Differences🛑: Stops liquid junction potential.

⚡️ EMF of a Cell :

🌿When two electrodes connect, current moves from higher potential to lower potential. The difference in potential that drives this current is called the EMF of the cell.

🌿Ecell = E Cathode - E Anode

🌿Here, E cathode and E Anode are the reduction potentials of the cathode and anode, respectively.

🔹 Understanding Electrode Potential:

🌿When a metal meets its electrolytic solution, it picks up a charge, resulting in electrode potential. This reflects the metal's tendency to either lose or gain electrons.

⚡️ Oxidation Potential: Metal's tendency to lose electrons.
⚡️ Reduction Potential: Metal's tendency to gain electrons.

🔹Standard Electrode Potential:

🌿At a specific temp, it's a metal's tendency to oxidize or reduce when in contact with a 1M ion solution.

🌿SRP (Standard Reduction Potential): It's the tendency of a substance to undergo reduction.
🌿SOP (Standard Oxidation Potential): It's the tendency of a substance to undergo reduction.

🌟Thermodynamics of EMF of Cells

🧬Relationship between Enthalpy Change and EMF:

🌿Using the Gibbs-Helmholtz equation:

Combining equations (1) and (2):

🔹Nernst Equation & Its Derivation:

🌿The Nernst Equation helps us find cell or electrode potential in non-standard conditions. It connects the measured potential to the reaction quotient.

🔸Deriving the Equation:

🌿Consider a redox reaction: aA + bB → cC + dD .. make this in

	Creado por Shoeb Ahmed hace más de 2 años

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