Collin
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Why are Titration experiments repeated??
Why do titration experiments (acid-base titration, with an unknown acid and a known base) have to be repeated a couple of times - and why do the the
different repeatings often give a somewhat significant difference in the results???
[Edited on 18-5-2006 by Collin]
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guy
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Its supposed to give you more accurate results. If you do any quantitative experiment once, you are relying only on one experiment that could be
wrong. If you do it many times, you can see a trend and see if you are precise (not necessarily accurate). If you have significant differences in
your results, you are doing something wrong.
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Collin
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Yes I know.. But, any more specifc explenation? Its for my conclusion for my assignment. I have to tell what could have gone wrong and I have no
idea.. Is it because base/acid sometimes react differently? It shouldnt be, should it
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12AX7
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So sources of error? Everything, especially things involving humans (measuring, etc.).
I mean there's nothing hard about estimating sources of error, look at the procedure and figure what an error here or a drop there or a grain of salt
there will do to the results. Certain procedures (e.g. weigh by difference) are inherently more accurate than others (transferring a weight of
powder), etc.
Tim
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midnite13
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| Quote: | Originally posted by Collin
Why do titration experiments (acid-base titration, with an unknown acid and a known base) have to be repeated a couple of times - and why do the the
different repeatings often give a somewhat significant difference in the results???
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The first time you initiate your titration, the value you get should give you an indication of the equivalence point.
The second time, since you know how much of your standard solution is displaced before the equivalence point, you can adjust the stopcock of your
burette to drip slowly. This should give you a fairly accurate result.
Based on your observations from the second trial, your third titration should be the most accurate of them all.
Hope this helps (=
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