What is electrode potential in Chemistry class 12

 

Electrode potential in chemistry refers to the ability of an electrode (metal or non-metal) to lose or gain electrons when it is in contact with a solution of its own ions. It is a measure of the tendency of a chemical species to be reduced (gain electrons) or oxidized (lose electrons).

🔹 Definition:

Electrode potential is the potential difference developed between a metal electrode and its ion solution when they are in contact.

🔹 Types of Electrode Potential:

  1. Oxidation Potential:

    • Tendency of an electrode to lose electrons.
    • Example: Zn → Zn²⁺ + 2e⁻

  2. Reduction Potential:

    • Tendency of an electrode to gain electrons.
    • Example: Cu²⁺ + 2e⁻ → Cu

Usually, we refer to Standard Reduction Potential (E°) in data tables.

🔹 Standard Electrode Potential (E°):

  • Measured under standard conditions:
    • 1 M concentration
    • 1 atm pressure
    • 25°C (298 K)
  • Compared to a reference electrode: Standard Hydrogen Electrode (SHE), which is assigned 0.00 V.

🔹 Example:

Electrode Half-cell Reaction E° (V)
Cu²⁺/Cu Cu²⁺ + 2e⁻ → Cu +0.34
Zn²⁺/Zn Zn²⁺ + 2e⁻ → Zn -0.76
  • Copper has higher reduction potential → gets reduced easily.
  • Zinc has lower reduction potential → gets oxidized easily.

🔹 Importance:

  • Used in electrochemical cells (Galvanic/Voltaic cells).
  • Helps determine the direction of electron flow.
  • Predicts oxidizing and reducing strength of elements.

Would you like a diagram or example of a Galvanic cell using this concept?

Comments

Post a Comment

Popular posts from this blog

Faraday's First Law of Electrolysis (Chemistry, Class 12):

  Faraday's First Law of Electrolysis (Chemistry, Class 12): Statement: The mass (m) of a substance deposited or liberated at an electrode during electrolysis is directly proportional to the quantity of electricity (Q) passed through the electrolyte. Mathematically: m=Z.Q Where: m = mass of the substance deposited (in grams) Q = total charge passed (in coulombs) Z = electrochemical equivalent (ECE) of the substance (grams per coulomb) Also, Q = I.t I = current (in amperes) t = time (in seconds) So, m = Z.I.t In Simple Words: Faraday's First Law tells us that more electricity means more substance will be deposited at the electrode. For example, if you double the current or time, the amount of substance deposited will also double. If you want the Second Law of Faraday or its explanation in Hindi , just let me know!
Read more

What is electromotive force in Chemistry class 12th

  In chemistry , electromotive force (EMF) refers to the voltage generated by a chemical cell (like a galvanic or voltaic cell) due to redox (reduction-oxidation) reactions happening at the electrodes. 🔹 Definition (Chemistry Context): EMF is the potential difference between two electrodes of an electrochemical cell when no current is flowing . It measures the tendency of electrons to flow from the anode (where oxidation occurs) to the cathode (where reduction occurs). 🔹 Symbol: 🔹 Unit: Volt (V) 🔹 Formula: \mathcal{E}_{\text{cell}} = E^\circ_{\text{cathode}} - E^\circ_{\text{anode}} Where: = standard electrode potentials (in volts) Measured under standard conditions : 1 M concentration 25°C (298 K) 1 atm pressure 🔹 Example (Daniel Cell): Zn | Zn²⁺ (1 M) || Cu²⁺ (1 M) | Cu Anode (oxidation): Zn → Zn²⁺ + 2e⁻ Cathode (reduction): Cu²⁺ + 2e⁻ → Cu Standard electrode potentials: \mathcal{E}_{\text{cell}} = 0.34 - (-0.76) = 1.10\text{ V}...
Read more

What is means of isolated gaseous atom

  💨 Isolated Gaseous Atom – Meaning: An isolated gaseous atom means: 👉 A single atom of an element 👉 In the gaseous state (not bonded to any other atom or molecule) 👉 That is completely free from external forces (like other atoms or molecules nearby) 🧪 In Simple Words: An isolated gaseous atom is a lone atom in the gas phase, existing independently , just like: A single He atom (Helium) floating alone in space Not forming a molecule like O₂ or H₂ Not in solid or liquid form 🔍 Why Important in Chemistry? It is a reference state used in: Ionization energy Electron affinity Enthalpy calculations Bond dissociation energies These properties are usually measured for an isolated gaseous atom because: There's no interference from other atoms. It gives the purest form of an element's energy or behavior. 🧠 Example: If we say: "The ionization energy of an isolated gaseous hydrogen atom is 1312 kJ/mol" It means: the energy required...
Read more