How Much Acid is in
Fruit Juices and Soft
Drinks?
Lab E
AP Chemistry Guided-Inquiry Experiments The
College Board (2013). Investigation 4.
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Lab Tasks
S Design a plan for collecting data from an acid-base titration in order to
answer your developed scientific question.
S Select appropriate lab equipment, tools, and indicator to use in
performing a titration.
S Conduct and evaluate the results of an acid-base titration.
S Represent what is occurring at the molecular level with visual diagrams.
S Analyze data to identify patterns and relationships.
S Make predictions and provide an explanation for a real-world
application from the learning gleaned in this experiment.
Materials Available
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Beakers of various sizes (100mL,
150mL, 250mL, and 400mL)
Buret (50mL)
Erlenmeyer flasks (125mL and
250mL)
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Acid-Base Indicators
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pH meter and paper
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0.10M acetic acid
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Sprite, Diet Sprite, Pineapple
Juice (MUST BE LIGHTCOLORED!)
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0.10M NaOH
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0.25M NaOH
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DI Water
Graduated cylinders ( 10mL,
25mL, and 100mL)
Volumetric Pipets (10mL, 25mL)
Droppers
Safety and Disposal
S Goggles must be worn
AT ALL TIMES!
S NaOH is a skin irritant
and can cause burns.
S Was hands with soap
and water after
completing the lab.
S After neutralization
solutions may be washed
down the drain with lots
of water.
Lab “Warm-up”
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Write a complete chemical equation for the reaction of a solution of sodium
hydroxide (NaOH) with hydrochloric acid (HCl).
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How many mL of 0.1M HCl are required to react completely with 5mL of 0.1 M
NaOH?
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If equal molar amounts of NaOH and HCl are mixed, when the reaction is
complete what will be the chemical species in the resulting solution?
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What will be the pH of the mixture in the above situation? Explain.
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Write the complete chemical equation for the reaction of a 0.1M solution of
acetic acid with a 0.1M solution of NaOH.
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How many mL of 0.1 M NaOH solution will be required to react completely
with 5mL of a 0.1M acetic acid solution? Explain.
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How is it possible to determine when an acid-base reaction is complete when the
concentration of one of the reactants is unknown?
Pre-Lab Assignment pg 41
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1. Identify a research question pertaining to acid concentration in fruit
juices and sodas. Propose a hypothesis that answers your question, and
then outline a tentative procedure. Be sure to clearly identify which pieces
of equipment you plan to use during your investigation.
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2. Make a simple sketch showing how you plan to set up your equipment,
labeling the following: analyte, titrant, buret, Erlenmeyer flask, volumetric
pipette.
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3.Be prepared to discuss with and finalize an investigation with your lab
partner tomorrow! Your plan will then be proposed to Mrs. Bechtum.
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4. Labs will be approved and conducted TOMORROW! Be prepared.
Safety and Disposal
S Goggles must be worn
AT ALL TIMES!
S NaOH is a skin irritant
and can cause burns.
S Was hands with soap
and water after
completing the lab.
S After neutralization
solutions may be washed
down the drain with lots
of water.
Lab Day… and Beyond!
S Consult with your partner to
finalize a question and
procedure. (10-15 minutes)
S Approval from Mrs. Bechtum
(5-10 minutes)
S Data Collection (60 Minutes)
S Lab Report Completed
INDIVIDUALLY!
S Lab Report Due Monday,
September 8th!!
S Complete Data Collection and
Computation
S 1, 2, (Omit 3 & 4)
S Complete Post-Lab Assessment
S 1, 2, 3, 4, and 7 (Omit 5 and 6)