# pH notation in text

When referring to units of pH in continuous text (i.e. not in a table), which is the recommended usage?

• pH 7 to pH 8
• pH 7 to 8

What about when the term "pH" has already been mentioned in the text?

• the pH was increased from 7 to 8
• the pH was increased from pH 7 to 8
• the pH was increased from pH 7 to pH 8
• the pH value was increased from 7 to 8
• Using pH twice in any of those sentences is redundant. – MaxW Feb 3 '17 at 22:56
• Additionally, would it be correct to refer to pH as a measure of acidity? Or would this be ambiguous with the acid dissociation constant? – Marcel Feb 3 '17 at 23:22
• If your readers are chemists then saying that "pH as a measure of acidity" is ludicrous. If you are writing an article for a newspaper about mine water discharge then through the phrase into the article. – MaxW Feb 3 '17 at 23:36
• In a dilute solution, is not pH an appropriate measure of acidity? Constant references to hydrogen ion activity become tedious. – Marcel Feb 3 '17 at 23:45
• $$\ce{<-->[He went that way!]}$$ The point is that chemists know pH is a measure of acidity. You don't have to explain it every time you use the term. – MaxW Feb 3 '17 at 23:50