JEE Chemistry Intermediate Topics
Equilibrium and Ionic Equilibrium
CHEMICAL EQUILIBRIUM:
For aA + bB ⇌ cC + dD:
Kc = [C]^c[D]^d / ([A]^a[B]^b)
Kp = Kc(RT)^Δn where Δn = moles of gas products - moles of gas reactants
Le Chatelier's Principle:
Add reactant → shifts right | Remove product → shifts right
Increase pressure → shifts to side with fewer moles of gas
Increase temperature → shifts in endothermic direction (absorbs heat)
Degree of dissociation (α):
For A ⇌ nB: if initial moles = 1, at equilibrium: (1-α) A, nα B
Total moles at equilibrium = 1 - α + nα = 1 + (n-1)α
IONIC EQUILIBRIUM:
pH = -log[H⁺] | pOH = -log[OH⁻] | pH + pOH = 14 at 25°C
Strong acids: HCl, H₂SO₄, HNO₃, HBr, HI, HClO₄
Strong bases: NaOH, KOH, Ba(OH)₂, Ca(OH)₂
Weak acid: Ka = [H⁺][A⁻]/[HA]
[H⁺] = √(Ka × C) for weak acid of concentration C
pH = ½(pKa - log C) = ½pKa + ½pC
Buffer solution:
Henderson-Hasselbalch: pH = pKa + log([Salt]/[Acid])
Best buffer at pH = pKa (equal concentrations of acid and salt)
Solubility product: Ksp = [Cation]^m [Anion]^n
Precipitation occurs when ionic product > Ksp
Common ion effect: decrease in solubility when common ion added
Electrochemistry
GALVANIC CELL:
Cell notation: anode | anode solution || cathode solution | cathode
Anode: oxidation (negative electrode, loses electrons)
Cathode: reduction (positive electrode, gains electrons)
EMF of cell: E_cell = E_cathode - E_anode (reduction potentials)
Nernst equation: E = E° - (0.0592/n) log Q (at 25°C)
At equilibrium: E = 0, so E° = (0.0592/n) log K
Relation: ΔG° = -nFE° | ΔG° = -RT ln K
ELECTROLYSIS:
Faraday's 1st law: mass deposited ∝ charge (Q = It)
Faraday's 2nd law: mass ∝ equivalent weight
Mass deposited: m = (M × I × t) / (n × F)
where M = molar mass, n = n-factor, F = 96500 C/mol
Products of electrolysis:
At cathode: cation with highest reduction potential reduced
At anode: anion with lowest oxidation potential oxidized (or O₂ from H₂O)
Study Resources
•JD Lee Concise Inorganic Chemistry — comprehensive for inorganic + coordination
•MS Chauhan Organic Chemistry — excellent for organic mechanisms and reactions
•NCERT Exemplar Chemistry — extra problems beyond NCERT, JEE level
•Unacademy / Vedantu JEE Chemistry — chapter-wise live and recorded sessions