1. DO NOW: What is pH a measure of?

2. The pH scale pH  pH is the -log of the hydrogen ion concentration  Mathematically it is represented by the equation:  pH = -log [H 3 O + ] or pH = -log [H + ]  [H + ] and [H 3 O + ] are basically the same, but H 3 O + is hydronium ion and results when H + is in water.  [H 3 O + ] or [H + ] is the molarity of hydrogen ions  Low pH corresponds to acidity  High pH corresponds to basic.

3. pH = 1 ∴ [H 3 O + ]= 1 X 10 -1 moles/liter ∴ [OH - ] = 1 x 10 -13 moles/liter pH = 7 ∴ [H 3 O + ]= 1 X 10 -7 moles/liter ∴ [OH - ]= 1 X 10 -7 moles/liter pH = 10 ∴ [H 3 O + ]= 1 X 10 -10 moles/liter ∴ [OH - ]= 1 X 10 -4 moles/liter

4. Think about it and discuss with your partner(s) Why should we be concerned with pH of solutions/ substances in terms of the environment?

5. Resources Acids and basis – http://www.s-cool.co.uk/gcse/chemistry/acids- and-alkalis/revise-it/acids-alkalis-and-neutral- substances http://www.s-cool.co.uk/gcse/chemistry/acids- and-alkalis/revise-it/acids-alkalis-and-neutral- substances Hazardous waste classification – http://ccelearn.csus.edu/wasteclass/mod6/mod6 _16.html http://ccelearn.csus.edu/wasteclass/mod6/mod6 _16.html