CH3-COOH ⇄ H⁺ + CH3-COO⁻
initial: [CH3COOH] = c [H⁺] =0 [CH3COO⁻] =0
la ionizare: cα cα cα
la echilibru: c(1-α) cα cα
pH = 3⇔ [H⁺] = 10⁻³ mol/l = cα
Ka = [H⁺]² /[CH3COOH]
1,8·10⁻⁵ = c²α² / c(1-α) = cα·α /(1-α) = 10⁻³·α /(1-α)
α = 0,018(1-α)
1,018α = 0,018 ⇒ α = 0,0176
