AcidBase Titration

1
Acid-Base Titration

• Experiment 29, Choice I

2
Acid-Base Reactions

• The reaction of an acid with a base will produce
  a salt and water.
• Example
• HCl NaOH ? NaCl H2O

3
Titration

• Titration is a technique or procedure used to
  determine the concentration of an unknown
  solution.
• Standard Solution is a solution of known
  concentration.
• By determining how much of the unknown solution
  you need to neutralize the standard solution, you
  can calculate the concentration of the unknown
  solution.

4
Sample Calculation

• Lets use the following example
• You used a standard solution of 0.1M NaOH. It
  took 50mL of the 0.1M NaOH to neutralize 25mL of
  HCl.
• First, you need to write out the complete
  balanced equation!

5
Sample Calculation

• 0.050L NaOH x 0.1mol NaOH x 1mol HCl
• 0.025L HCl 1L NaOH 1mol NaOH
• 0.2M HCl
• Note for an explanation of average deviation see
  Appendix D, page 589 of your lab manual.

6
Using A Volumetric Flask

• You will be using a volumetric flask to make your
  standard NaOH solution.
• Volumetric flasks are used because they are more
  accurate than beakers or Erlenmeyer flasks.

7
Using A Volumetric Flask

• There is a line on the neck of your flask.
• If you are using a 1L flask, this line represents
  the 1L mark.
• Dissolve your solid in distilled water.
• Once dissolved, add water up to this line.

8
Using A Volumetric Flask

• To make sure your solution is thoroughly mixed,
  invert the flask several times.
• Make sure to hold the bottom of the flask and the
  stopper as you invert the flask.

9
Procedure Notes

• Make sure to record the exact weight of your KHP.
  
• Be very careful and exact when making your KHP
  solution. If you are off, your NaOH
  concentration calculations will be wrong.
• After you standardize your NaOH solution, you
  will perform the analysis of vinegar only, not of
  a solid acid.

10
More Procedure Notes

• Putting a piece of white paper under your
  reaction flask will help you better notice the
  light pink color of your endpoint.
• If your solution is dark pink, you passed your
  endpoint.
• Store your excess standardized NaOH solution for
  use next week. Put your name and class section
  on the bottle and place it on the bottom of the
  cart!!!!!