Question

A solution was prepared with 0.219 mol of pyridinium fluoride

(C5H5NHF) and enough water to make a 1.00 L. Pyridine (C5H5N) has a
Kb=1.70×10−9 and HFHF has a Ka=6.30×10−4.
Calculate the pH

Answer 1

To calculate the pH of the solution, we need to consider the equilibrium between pyridinium fluoride (C5H5NHF) and its dissociation products, pyridine (C5H5N) and HF.

Step-by-step explanation:

To calculate the pH of the solution, we need to consider the equilibrium between pyridinium fluoride (C5H5NHF) and its dissociation products, pyridine (C5H5N) and HF. First, we need to determine the concentration of HF in the solution by using the equation: Kb = [Pyridine][HF] / [Pyridinium Fluoride]. We can set up an ICE table to solve for the concentration of HF. Then, we can use the Ka of HF to calculate the concentration of H3O+ ions in the solution and convert it to pH.

Answer 2

Calculating pH for a solution containing weak base pyridine and its conjugate acid pyridinium fluoride requires using the Kb of pyridine and Ka of HF to find the pKa, then applying Henderson-Hasselbalch equation.

Step-by-step explanation:

The calculation of pH for a solution containing a weak base, pyridine (C5H5N), and its conjugate acid, pyridinium fluoride (C5H5NHF), involves several steps. First, we must recognize that the fluoride anion (F-) from pyridinium fluoride will react with water to form HF and OH-. We have to use the Kb value of pyridine and Ka of HF to find the pKa of pyridinium ion and subsequently apply the Henderson-Hasselbalch equation. With the information given, we can calculate the pH of the 1.00 L solution with 0.219 mol of C5H5NHF, but we'll need additional steps to calculate the concentrations of the various species in the solution before we can find the pH.