Consider the titration of 300.0 mL of 0.414 M NH₃ (K_b = 1.8 ×10^-5)with 0.500 M HNO₃.After 150.0 mL HNO₃ has been added,what is the pH of the solution? A) 4.93 B) 9.07 C) 6.07 D) 11.07 E) 7.00

Question

Quizplus · Accepted Answer

The pH after adding 150.0 mL of 0.500 M HNO3 to 300.0 mL of 0.414 M NH₃ can be found by first determining the reaction's equivalence point and then calculating the pH based on the remaining species in solution. Given the strong acid (HNO3) neutralizes the weak base (NH₃), the solution will contain the conjugate acid of the weak base. The pH can be calculated using the Kb of the weak base's conjugate acid and the concentrations of the species in solution. Since the question implies a weak base being titrated with a strong acid, and given the Kb and the volumes and concentrations, the solution will be slightly basic at the halfway point to the equivalence point, which is why option B is correct, indicating a basic pH but not as high as would be in a fully basic solution.

Consider the Titration of 300