Ionic-Equillibrium-5-By-Prof-Shashank-Deep
1 : Acids and Bases
- Arrhenius Theory: Defines acids as substances that produce H⁺ ions (protons) in aqueous solutions and bases as substances that produce OH⁻ ions.
- Brønsted-Lowry Theory: Defines acids as proton (H⁺) donors and bases as proton acceptors.
2 : pH and pOH
- pH: A measure of the hydrogen ion concentration in a solution.
- pH = -log[H⁺], where [H⁺] is the hydrogen ion concentration.
- pOH: A measure of the hydroxide ion concentration in a solution.
- pOH = -log[OH⁻], where [OH⁻] is the hydroxide ion concentration.
- For a neutral solution at 25°C, pH + pOH = 14.
3 : Ionization Constant (Ka and Kb)
- Ka (Acid Dissociation Constant): Measures the extent of ionization of a weak acid.
- Ka = [H₃O⁺][A⁻] / [HA]
- Kb (Base Ionization Constant): Measures the extent of ionization of a weak base.
- Kb = [OH⁻][BH⁺] / [B]
4 : pKa and pKb
- pKa: The negative logarithm (base 10) of the Ka value. It indicates the strength of an acid.
- pKa = -log(Ka)
- pKb: The negative logarithm (base 10) of the Kb value. It indicates the strength of a base.
- pKb = -log(Kb)
- pKa + pKb = 14 at 25°C.
5 : Henderson-Hasselbalch Equation
- Used for buffer solutions.
- pH = pKa + log([A⁻] / [HA])
6 : Common Ion Effect
- When a salt is added to a solution that already contains one of the ions from the salt, it reduces the ionization of the weak electrolyte.
7 : Hydrolysis
- When salts react with water, they can undergo hydrolysis to produce acidic or basic solutions.
- The extent of hydrolysis depends on the value of the equilibrium constant (Kw) and the ionization constants (Ka and Kb).
8 : Solubility Product (Ksp)
- Ksp represents the equilibrium constant for the dissolution of a sparingly soluble salt in water.
- The solubility of a salt depends on the value of Ksp.
9 : Le Chatelier’s Principle
- When a system at equilibrium is subjected to a change in concentration, temperature, or pressure, it will shift its position to counteract the change.
10 : Buffer Solution
- Buffers are solutions that resist changes in pH when an acid or base is added.
- Made by mixing a weak acid and its conjugate base or a weak base and its conjugate acid.
11 : Salt Hydrolysis
- Salts derived from weak acids and strong bases produce basic solutions.
- Salts derived from strong acids and weak bases produce acidic solutions.
- Salts derived from weak acids and weak bases undergo hydrolysis to produce solutions with a pH determined by the relative strengths of the acids and bases involved.
12 : Common Strong Acids and Bases
- Common strong acids include HCl, H2SO4, HNO3, and HClO4.
- Common strong bases include NaOH, KOH, and Ba(OH)2.
13 : Autoionization of Water
- Kw (Ionic Product of Water) at 25°C = 1.0 x 10^-14.
- Kw = [H₃O⁺][OH⁻].