Ask Question
19 April, 07:22

The ka of hypochlorous acid (hclo) is 3.0 ⋅ 10-8 at 25.0 °c. calculate the ph of a 0.0375m hypochlorous acid solution.

+5
Answers (1)
  1. 19 April, 07:24
    0
    We can set up an ICE table for the reaction:

    HClO H + ClO-

    Initial 0.0375 0 0

    Change - x + x + x

    Equilibrium 0.0375-x x x

    We calculate [H+] from Ka:

    Ka = 3.0x10^-8 = [H+][ClO-]/[HClO] = (x) (x) / (0.0375-x)

    Approximating that x is negligible compared to 0.0375 simplifies the equation to

    3.0x10^-8 = (x) (x) / 0.0375

    3.0x10^-8 = x2/0.0375

    x2 = (3.0x10^-8) (0.0375) = 1.125x10^-9

    x = sqrt (1.125x10^-9) = 0.0000335 = 3.35x10^-5 = [H+]

    in which 0.0000335 is indeed negligible compared to 0.0375.

    We can now calculate pH:

    pH = - log [H+] = - log (3.35 x 10^-5) = 4.47
Know the Answer?
Not Sure About the Answer?
Find an answer to your question 👍 “The ka of hypochlorous acid (hclo) is 3.0 ⋅ 10-8 at 25.0 °c. calculate the ph of a 0.0375m hypochlorous acid solution. ...” in 📗 Chemistry if the answers seem to be not correct or there’s no answer. Try a smart search to find answers to similar questions.
Search for Other Answers