The pH of aqueous 0.50 M hypobromous acid,HBrO,is 4.45.What is the K_a of this acid?

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Quizplus · Accepted Answer

The pH of the solution is 4.45, which means the concentration of H+ ions is 10^-4.45. For a weak acid like HBrO, the Ka can be calculated using the formula Ka = [H+][A-]/[HA], where [H+] = [A-] due to the 1:1 stoichiometry of dissociation, and [HA] is the initial concentration minus [H+]. Given the small Ka value typically associated with weak acids, the change in initial concentration ([HA]) can be considered negligible. Therefore, Ka ≈ [H+]^2 / [HA] = (10^-4.45)^2 / 0.50 = 2.5 × 10^-9.

The PH of Aqueous 0