Summary Study Guide Electrochemistry | Chemistry | 2025/2026

🔹 1. Electrochemical Cells & EMF (10 Marks)
An electrochemical cell converts chemical energy into electrical energy through redox reactions.
Types:.Galvanic cell (spontaneous).
Electrolytic cell (non-spontaneous)
Working:
 Oxidation at anode
 Reduction at cathode
 Electrons flow through external circuit
EMF of Cell:

E_{cell} = E_{cathode} - E_{anode}

Nernst Equation:

E = E^0 - \frac{0.0591}{n} \log Q

Applications:
 Batteries (dry cell, lead-acid)
 Corrosion studies
 Electroplating



🔹 2. Conductance Measurements (10 Marks)
Conductance (G) is the ability of a solution to conduct electricity.
Types:
 Specific conductance
 Molar conductance
Measurement:
 Using conductivity cell + Wheatstone bridge
Factors:
 Concentration
 Temperature
 Nature of electrolyte

, Applications:
 Determination of degree of dissociation
 Conductometric titration
 Water purity analysis



🔹 3. Acid–Base Theories (10 Marks)
Arrhenius Theory:
 Acid → gives H⁺
 Base → gives OH⁻
Bronsted–Lowry Theory:
 Acid → proton donor
 Base → proton acceptor
Lewis Theory:
 Acid → electron pair acceptor
 Base → electron pair donor
Comparison:
 Lewis theory is most general



🔹 4. Buffer Solution & Henderson Equation
(10 Marks)
A buffer resists change in pH.
Types:
 Acidic buffer (weak acid + salt)
 Basic buffer (weak base + salt)
Henderson Equation:

\text{pH} = pK_a + \log \frac{[Salt]}{[Acid]}

Importance:
 Biological systems
 Pharmaceuticals
 Industrial processes