pH = pKa + log([A-]/[HA])
where:
pH is the pH of the buffer
pKa is the acid dissociation constant of the weak acid
[A-] is the concentration of the conjugate base
[HA] is the concentration of the weak acid
In the case of triethylammonium acetate buffer, the weak acid is acetic acid (CH3COOH), and the conjugate base is triethylammonium acetate (CH3COO-NEt3). The pKa of acetic acid is 4.76.
Let's say we have a triethylammonium acetate buffer with a concentration of 0.1 M acetic acid and 0.1 M triethylammonium acetate. Plugging these values into the Henderson-Hasselbalch equation, we get:
pH = 4.76 + log(0.1/0.1)
pH = 4.76 + 0
pH = 4.76
Therefore, the pH of the triethylammonium acetate buffer is 4.76.
