Question

Question 4 Listen Find the pH (with two decimal places) of a solution 0.40 Min HF, and 0.64 M in NaF. For HF Ka=6.6x10-4 Report your answer to two decimal places. Your Answer: Answer

Answer 1

Answer and Explanation:

To find the pH of the solution, we need to determine the concentration of the hydronium ion (H3O+) in the solution. Since we have a weak acid (HF) and its conjugate base (NaF), we can use the concept of the Henderson-Hasselbalch equation:

pH = pKa + log([A-]/[HA])

First, let's calculate the concentrations of HF and NaF in the solution:

[H3O+] = [HF] = 0.40 M (concentration of HF)

[OH-] = [F-] = 0.64 M (concentration of NaF)

Next, we need to determine the pKa value for HF. The pKa is the negative logarithm of the acid dissociation constant (Ka):

pKa = -log(Ka)

pKa = -log(6.6x10^-4)

pKa = 3.18

Now, let's substitute the values into the Henderson-Hasselbalch equation:

pH = 3.18 + log([0.64]/[0.40])

pH = 3.18 + log(1.6)

pH = 3.18 + 0.2041

pH ≈ 3.38

Therefore, the pH of the solution is approximately 3.38.