Pure Solutions
Buffers
Acid-Base Mixtures
Salt Solutions
Concentration [C]0.100 M
Ka (acid)10^-4.7 pKa=4.74
Titration
Acid vol25 mL
Base conc0.10 M
Base added0.00 mL
📐 pH Formula — Weak Acid (WA)
[H⁺] = √(Ka · C)
pH = ½pKa − ½logC
pH = ½(4.74) − ½log(0.100)
pH = 2.87
OR exact: [H⁺]² + Ka[H⁺] − Ka·C = 0
• α = √(Ka/C) = 1.35% dissociation
• Approximation valid when α < 5%
pH
2.87
🔴 Acidic
0714
Solution
🔴 H⁺🔵 OH⁻🟢 H₂O
Live Values
[H⁺]1.34e-3 M
[OH⁻]7.46e-12 M
pOH11.13
pKa4.74
% dissoc1.34%
HA ⇌ H⁺ + A⁻
Ka = x²/(C-x) ≈ x²/C
[H⁺] = x = √(Ka·C)
Titration Curve
Drag "Base added" or click Auto-Titrate
Equiv: 25.0 mL
Half-eq: 12.5 mL → pH=pKa