Hi daisy001:
The pH scale is used because the range of concentration of hydrogen
ions is so HUGE that using the concentration values would quickly
become meaningless.
The pH scale is logarithmic (i.e., it works on multiples of 10) like
the Richter scale for earthquakes.
Here's some sites that explain it better than I could:
What is pH?
URL: http://antoine.frostburg.edu/chem/senese/101/acidbase/faq/what-is-pH.shtml
Quote: "The pH scale was defined because the enormous range of
hydrogen ion concentrations found in aqueous solutions make using H+
molarity awkward. For example, in a typical acid-base titration, [H+]
may vary from about 0.01 M to 0.0000000000001 M. It is easier to write
'the pH varies from 2 to 13'."
The pH scale
URL: http://www.ec.gc.ca/water/en/manage/qual/e_ph.htm
Quote: "Because the scale is logarithmic, a difference of one pH unit
represents a tenfold change. For example, the acidity of a sample with
a pH of 5 is ten times greater than that of a sample with a pH of 6. A
difference of 2 units, from 6 to 4, would mean that the acidity is one
hundred times greater, and so on."
Search Strategy (on Google):
* "ph scale" rather concentration
* "ph scale" logarithmic
I hope this helps.
websearcher |
