Muscles produce lactic acid, CH3CH(OH)COOH(aq) , during exercise. Calculate the percent ionization (deprotonation), pH, and pOH of a 0.1029 M solution of lactic acid. The acid‑dissociation (or ionization) constant, Ka , of this acid is 8.40×10−4
I'm having a bit of trouble finding the pH and pOH. I keep getting pH 2.01, but when the website gives me feedback, it's saying I assumed that x was negligible. However, in my work, I solved the question entirely with a quadratic, so I don't understand why it's telling me that. If it helps, the ionization percent of 8.75% was confirmed to be correct.
Finding pH and pOH
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Re: Finding pH and pOH
Hi, when I solved it I got pH= 2.05, pOH=11.95, and % ionization = 8.64. On my achieve I had a different initial concentration so I can't check if this is correct, but when I did use the approximation I got pH= 2.03, pOH=11.97, and % ionization = 9.04. Perhaps trying solving again to see if it is a calculation error! Hope this helps!
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Re: Finding pH and pOH
I just plugged your numbers into the exact formulas I solved mine with, and got the same answer you did. I got the problem correct, so this is weird. Have you tried inputting your answer with more significant digits?
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Re: Finding pH and pOH
Hi! My numbers were pretty similar to yours and I got a pH of 2.05, but my H3O+ value was .000887. You might need more digits when using -(log)?, I can't see why else your calculations would be off.
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