9-12. pOH
pOH is mathematically defined as:
-log [OH-] or log 1/[OH-]
NOTE:
pH and pOH have no unit of report.
9-13. pH SCALE
a. pH range: 0-14
b. Neutral: pH 7
c. Acidic: less than pH 7
d Basic: greater than pH 7
pH below 7
pH = 7
pH above 7
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0
14
More
Neutral
More
Acidic
Basic
In examining the definition of pH, we find that there is an inverse relationship
+
between hydrogen ion concentration and pH. As [H ] increases, pH decreases and vice
versa. Also, notice that each increase of one unit on the pH scale corresponds to a
tenfold decrease in [H+], and each decrease of one unit on the pH scale corresponds to
+
+
-
a tenfold increase in [H ]. If this is true, then as the [H ] increases, [HO ] decreases,
+
-
and as [H ] decreases, [OH ] increases.
9-14. pOH SCALE
a. pOH range: 0 -14
b. Neutral: pOH 7
c. Acidic: greater than pOH 7
d. Basic: less than pOH 7
pOH below 7
pOH = 7
pOH above 7
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0
14
More
Neutral
More
Basic
Acidic
MD0837
9-11