10.3: Acid-Base Stoichiometry and Titrations
Terminology
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Titration – a laboratory process that is ________________________________________________
____________________________________ by reacting it with a solution of a known concentration.
•
Titrant – the ____________________________ during a titration. Concentration is _____________
**In an acid base titration, one solution is _________________, the other solution is ____________.
We want to see the exact moment when _________________________ occurs. We use an
indicator and gradually add one solution to the other until a ___________________________ colour
change is observed.
•
Equivalence point – the point during a titration at which the ______________________________
______________________________is stoichiometrically equal to the _______________________
___________________________________.
•
•
pH changes extremely quickly and sharply!
Endpoint – the point during a titration when the ___________________________________.
What’s the difference?
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EQUIVALENCE POINT is ________________________________
•
ENDPOINT is _________________________________
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The goal is to do the titration very carefully and precisely so that your ________________________
________________________________________________________________________________
Titration Setup and Results
The pH changes VERY drastically at
the equivalence point. Just 1 drop of
titrant can change the pH from 3 to
11!
Titration Labware
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Volumetric Flask – used to _______________________________________________ (the solution
of _________________ concentration).
•
Glass funnel – the standard solution is _____________________________________________ by
pouring through the funnel.
•
Burette – a calibrated tube used to dispense very ________________________________________
_________________________________________________ into the flask below. The rate of flow is
adjusted with a stopcock near the bottom.
•
Pipette – used to _________________ precise and accurate volumes of the _________________
_________________________________________ to the Erlenmeyer flask.
•
Erlenmeyer flask – the ________________________________________________ is placed in this.
Titration Procedure
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Follow pg 479-480 in textbook
Titration Calculations
1. Collect data from at least 3 trials! (see table)
2. Calculate average volume of titrant used (convert to L).
3. Write balanced equation for reaction. Fill in chart for values that you have.
4. Use stoichiometry to determine the concentration of your acid.
Trial #
Initial burette reading (mL)
Final burette reading (mL)
Volume of base (titrant) added (mL)
1
2
3