Question

For the titration of 45.0 mL of 0.350 M NH3 with 0.500 M HCl at 25 °C, determine the relative pH at each of these points.

(a) before the addition of any HCl
(b) after 18.0 mL of HCl has been added
(c) after 33.0 mL of HCl has been added

Answer 1

The relative pH at each point in the titration can be determined using the Henderson-Hasselbalch equation.

Step-by-step explanation:

The relative pH at each point in the titration can be determined by using the Henderson-Hasselbalch equation. The equation is pH = pKa + log([A-]/[HA]), where pKa is the negative logarithm of the acid dissociation constant, [A-] is the concentration of the conjugate base, and [HA] is the concentration of the weak acid. In this case, NH3 is the weak base and HCl is the strong acid.

Answer 2

(a) before the addition of any HCl: pH>7
(b) after 18.0 mL of HCl has been added : pH<7
(c) after 33.0 mL of HCl has been added : pH<7