1. pH NOTES

2. What is “pH”?
• The term "pH" was invented in
1909 by the Danish chemist
Soren Sorensen
• pH was originally written by Dr
Sørensen as pH, and it stands
for pondus hydrogenii which
means "potential hydrogen". The
terminology refers to acidity
being due to a predominance of
hydrogen ions in an aqueous
(water containing) solution.

3. Acids and Bases
Acid = compounds that release hydrogen
ions (H+
) in solution. (ex. HCl)
Base = produce OH-
ions in solution (ex.
sodium hydroxide)
Acid Base

4. pH scale
pH scale = the scale of acidity or
basicity from 1 to 14.
1 (strong acid) 14 (strong base)
7 (neutral) [H+
] = [OH-
]

5. High OH-
Concentration
Low OH-
Concentration

6. High OH-
Concentration
Low OH-
Concentration