EQUILIBRIUM (PC-06)
│
├── CHEMICAL EQUILIBRIUM
│   ├── Definition
│   │   ├── Dynamic: rates of forward = backward
│   │   ├── Concentrations constant (not equal)
│   │   └── Reversible reactions only
│   │
│   ├── Equilibrium Constants
│   │   ├── Kc = [products]^coeff / [reactants]^coeff
│   │   ├── Kp = Kc(RT)^$\Delta n$ [gaseous reactions]
│   │   ├── Only temperature changes K
│   │   └── $\Delta G$° = −RT ln K
│   │
│   ├── Reaction Quotient Q
│   │   ├── Q < K → forward shift
│   │   ├── Q > K → backward shift
│   │   └── Q = K → equilibrium
│   │
│   └── Le Chatelier's Principle
│       ├── Concentration → shifts (not K)
│       ├── Pressure → shifts toward fewer gas moles (not K)
│       ├── Temperature → shifts AND changes K
│       ├── Catalyst → no shift, no K change
│       └── Inert gas
│           ├── Constant V → no effect
│           └── Constant P → shift toward more gas moles
│
└── IONIC EQUILIBRIUM
    ├── Acid-Base Theories
    │   ├── Arrhenius ($H^{+}$/$OH^{-}$ in water)
    │   ├── Bronsted-Lowry (proton donor/acceptor)
    │   │   └── Conjugate pairs: Ka × Kb = Kw
    │   └── Lewis ($e^{-}$ pair acceptor/donor)
    │
    ├── pH Calculations
    │   ├── Kw = [$H^{+}$][$OH^{-}$] = 10^{-14} @ 25°C
    │   ├── pH + pOH = 14 @ 25°C
    │   ├── Weak acid: [$H^{+}$] = √(Ka·C)
    │   └── Buffer: pH = pKa + log([salt]/[acid])
    │
    ├── Salt Hydrolysis
    │   ├── SA + SB → pH = 7
    │   ├── SA + WB → pH < 7
    │   ├── WA + SB → pH > 7
    │   └── WA + WB → depends on Ka vs Kb
    │
    └── Solubility Product
        ├── Ksp = [cation]^m[anion]^n
        ├── Common ion → reduces solubility
        ├── Ionic product > Ksp → precipitation
        └── Selective precipitation (lower Ksp first)