- #1
JessicaHelena
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Homework Statement
Calculate the pH of a 0.20 M solution of iodic acid ##(HIO_3)##. ##K_a## for iodic acid is 0.17
Homework Equations
##K_a = \frac{[H^+][IO_3^-]}{[HIO_3]}##
The Attempt at a Solution
##[HIO_3] = 0.20## M.
The concentration of ##[H^+]## and ##[IO_3^-]## should be the same because
##HIO_3 + H_2O## ←→ ##H_3O^+ + IO^-##
Therefore, ##[H^+][IO_3^-] = 0.20 \times 0.17##, or ##[H^+] = \sqrt{0.20 \times 0.17}##. To find the pH, I can do ##-\log_{10} [H^+]##, which gives me 0.7343. However, that is apparently wrong.
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