Chem Help (in Off-topic)


AdminTitan [The Sky Forge] March 28 2010 8:57 PM EDT

Okay, either I'm crazy, or the website has the wrong answer. I got 2.04. The question is calculate the pH of .13M HF. HF's Ka is 6.8x10^-4.

DoS [Battle Royale] March 28 2010 9:20 PM EDT

Yeah, I too got 2.03 and we just went over this stuff in class

DoS [Battle Royale] March 28 2010 9:22 PM EDT

Haha, missed a - and got 2.03.. then added the negative and got 2.04

AdminTitan [The Sky Forge] March 28 2010 9:34 PM EDT

Evidently our book had 3.5*10^-4.

DoS [Battle Royale] March 28 2010 9:41 PM EDT

Now I get 2.18

JSCarnage March 28 2010 10:26 PM EDT

Maybe you could try this:

http://www.webqc.org/phsolver.php

Seems nice.

DoS [Battle Royale] March 28 2010 10:31 PM EDT

Nice JSCarnage!

Components of the solution (mixture):

Name: HF
Initial concentration = 0.13
Ka1 = 0.00035 ( pKa1 = 3.4559319556497 )

Answer:

[H+] = 0.0065726402681321
[OH-] = 1.5214585907715E-12
pH = 2.1822601367506
pOH = 11.817739863249

ScY March 28 2010 10:55 PM EDT

Chem=worst subject ever.
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