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- May 10, 2013
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What would be the pH of a 0.05M solution of acetic acid?
(From the passage & table you know that the Ka for acetic acid is approximated to be 2 x 10^-5)
A. 0.05
B. 2.0
C. 3.0
4. 6.0
First question, why can't you simply plug in 0.05 into the pH = -log [H] equation? Is it because 0.05 is not the H concentration?
Second, if I wanted to use the "shortcut" TBR equation for weak acids: pH = pka/2 - (log [HA])/2 how would I go about finding pKa knowing pKa = - log Ka.
Third, the other method of solving this question would be through the dissociation table to get, .00002 = x^2/.05, can someone work this out, I can't seem to get the correct answer unless I use a calc.
Lastly, are the methods listed the above the only way of solving this question or more importantly these types of questions? Again, thank you in advance!
(From the passage & table you know that the Ka for acetic acid is approximated to be 2 x 10^-5)
A. 0.05
B. 2.0
C. 3.0
4. 6.0
First question, why can't you simply plug in 0.05 into the pH = -log [H] equation? Is it because 0.05 is not the H concentration?
Second, if I wanted to use the "shortcut" TBR equation for weak acids: pH = pka/2 - (log [HA])/2 how would I go about finding pKa knowing pKa = - log Ka.
Third, the other method of solving this question would be through the dissociation table to get, .00002 = x^2/.05, can someone work this out, I can't seem to get the correct answer unless I use a calc.
Lastly, are the methods listed the above the only way of solving this question or more importantly these types of questions? Again, thank you in advance!