Ask Question
14 March, 15:44

What is the Kb value for a 0.17M solution of unknown with a pH of 9.45?

+3
Answers (1)
  1. 14 March, 18:15
    0
    Kb = 4.673 E-9

    Explanation:

    B (aq) + H2O (l) ↔ BH + (aq) + OH - (aq) Kb = [BH+][OH-] / [B] pH + pOH = 14

    ∴ C B = 0.17 M

    ∴ pH = 9.45

    ⇒ pOH = 14 - 9.45 = 4.55

    ⇒ pOH = - Log [OH-] = 4.55

    ⇒ [OH-] = 2.8184 E-5 M

    mass balance:

    ⇒ C B = 0.17 M = [B] + [BH+]

    charge balance:

    ⇒ [OH-] = [BH+] ... [H3O+] is neglected, it come frome the water

    ⇒ [B] = 0.17 - [BH+]

    ⇒ [B] = 0.17 - [OH-] = 0.17 - 2.8184 E-5

    ⇒ [B] = 0.16997 M

    ⇒ Kb = [OH-]² / [B]

    ⇒ Kb = (2.8184 E-5) ² / (0.16997)

    ⇒ Kb = 4.673 E-9
Know the Answer?
Not Sure About the Answer?
Find an answer to your question ✅ “What is the Kb value for a 0.17M solution of unknown with a pH of 9.45? ...” in 📘 Chemistry if you're in doubt about the correctness of the answers or there's no answer, then try to use the smart search and find answers to the similar questions.
Search for Other Answers