AP Chemistry Titration Virtual Lab
Please open the
simulation: http://www.chem.iastate.edu/group/Greenbowe/sections/projectfolder/flashfiles/
stoichiometry/acid_base.html
You can use another simulation to check your calculation for the initial pH of the acid solutions
by going to:
http://www.chem.iastate.edu/group/Greenbowe/sections/projectfolder/flashfiles/acidbasepH/
ph_meter.html
For this lab, you will compare the pH at various points during the titration of a strong acid vs.
strong base to the pH at the same points during the titration of a weak acid vs. strong base. You
need to do the calculations.
Activity 1. Go to the computer simulation and select "Strong Acid vs. Strong Base". Click fill the
buret with Base. Select HNO3 as the acid and KOH as the base. Select an indicator. The
computer will automatically assign you a molarity for the acid and a volume for the acid.
A. Calculate the pH of the acid before any base is added.
B. Add 10.0 mL of the KOH. Write a chemical equation that illustrates what happens when
HNO3 reacts with KOH.
C. Calculate the pH of the resultant solution, when you add 10.0 mL of the KOH. You will need
to titrate to the end point in order to determine the molarity of the base (see D).
AP Chemistry Titration Virtual Lab
D. Titrate to the end point, calculate the molarity of the base, enter this number and click-on
"OK". Then, go back and do part "C".
Activity 2. GOTO the computer simulation and select "Reset". Select "Weak Acid vs. Strong
Base". Click fill the buret with Base. Select CH3COOH as the weak acid and KOH as the base.
Select an indicator. The computer will automatically assign you a molarity for the acid and a
volume for the acid.
F. Calculate the pH of the weak acid before any base is added.
G. Add 10.0 mL of the KOH. Write a chemical equation that illustrates what happens when
CH3COOH reacts with KOH.
H. Calculate the pH of the resultant solution, when you add 10.0 mL of the KOH. You will need
to titrate to the end point in order to determine the molarity of the base (see I). Also write an
equation that illustrates what the equation is for the solution at this point in the titration.
I. Titrate to the end point, calculate the molarity of the base, enter this number and click-on
"OK". Calculate the pH at the equivalence point. Then, go back and do part "H".
AP Chemistry Titration Virtual Lab
Activity 3. Compare the amount of 0.200 M KOH needed to neutralize 50.0 mL of 0.200 M
HNO3 with the amount of 0.200 M KOH needed to neutralize 50.0 mL of 0.200 M CH3COOH. Is
the volume of KOH more, less, or the same? Explain and or show.
Activity 4: Open
http://www.mhhe.com/physsci/chemistry/animations/chang_7e_esp/crm3s5_5.swf. Try the
simulation and create the full graph.
1. As you do the titration, take a look at the particulate view. What do you notice happening as
you add NaOH? What is the difference in the beginning and the end picture?
2. Take a screenshot of the page using Fn Print Screen. Open Paint. Paste the screenshot into
Paint. In Paint, label the following parts of the graph: the initial pH of the acid, the point where
10 mL of KOH is added (and its pH), the equivalence point (and its pH). Save your modified
picture to the desktop, and then insert it into this document.