For the dissociation of a weak acid HA, the degree of dissociation α is given (approximately, when α ≪ 1) by:

1. HA ⇌ H⁺ + A⁻; K_a ≈ C α² / (1 − α). 2. For α ≪ 1, (1 − α) ≈ 1 and K_a ≈ C α² ⇒ α = √(K_a / C). 3. Hence dilute solutions (small C) have larger α — Ostwald's dilution law. _Source: NCERT Class 11 Chem Ch 7 §7.10 Ostwald's Dilution Law_