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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: 33LB on May 13, 2008, 02:48:09 PM

Title: Ethanoic Acid Question
Post by: 33LB on May 13, 2008, 02:48:09 PM

The pKa of ethanoic acid is 4.76. Calculate the pH of a 0.1M solution of ethanoic acid.

Thanks.

Title: Re: Ethanoic Acid Question
Post by: tamim83 on May 13, 2008, 03:17:54 PM

Use the acid ionization reaction for ethanoic acid and write the K_a expression.  The K_a is just the antiog of the pKa.  You need to find the euqilibrium concentration of H₃O⁺ (use an ICE table) and then you can figure out the pH.

Title: Re: Ethanoic Acid Question
Post by: 33LB on May 13, 2008, 04:52:20 PM

i've never heard of an ICE table. this is worth a small proportion of marks on the exam, so i think the answer is supposed to be very simple.

thanks. :)

Title: Re: Ethanoic Acid Question
Post by: Borek on May 13, 2008, 05:46:19 PM

http://en.wikipedia.org/wiki/ICE_table

http://www.chembuddy.com/?left=pH-calculation&right=pH-weak-acid-base

http://www.chembuddy.com/?left=BATE&right=pH-cheat-sheet