Chapter #16
Acid-Base Titration and pH
Chapter 16.1
• In the self-ionization of water, two water
molecules produce a hydronium ion and a
hydroxide ion by transfer of a proton.
• Kw= H3O+ OH• Kw= 1.0 X 10 -14 M2
• The pH of a solution is defined as the
negative of the common logarithm of the
hydronium ion concentration.
• The pH scale 0-14. 7 is neutral…pH<7
acid…pH>7 base
• pH= -log ( H3O+)
Chapter 16.2
• Acid-base indicators are compounds
whose colors are sensitive to pH.
• pH range over which an indicator changes
color is called its transition interval.
• pH meter determines the pH of a solution
by measuring the voltage between the two
electrodes that are placed in the solution.
• Titration is the controlled addition and
measurement of the amount of a solution
of known concentration required to react
completely with a measured amount of a
solution of unknown concentrations.
• Equivalence point is the point at which the
two solutions used in a titration are
present in chemically equivalent amounts.
• End point is the point in a titration at which
an indicator changes color.
Titration Problems
1. Balance equation
2. Use the known solution to figure out the
number of moles (M=mol/L)
3. Use the mole to mole ratio to figure out
the moles of the unknown.
4. Determine the Molarity of the unknown
using the given volume
• “Flask”. May 7, 2007.
http://www.chem.ualberta.ca/~iip/chem211i
rc/TotalSalt(start).jpg
• “Let’s Titrate”. May 7, 2007.
http://genchem.rutgers.edu/aanimate.gif
• “Titration curve”. May 7, 2007.
http://www.cofc.edu/~kinard/Applets/Weak
AcidTitration.gif