SCH3U Final Lab Exam January 2015
In this investigation, you will combine your chemistry knowledge and laboratory skills to
perform an investigation. This experiment and the final written report are worth 10% of
your final mark.
 You will be put into groups of 2 and will choose one of the following topics. Only
8 groups per topic.
 Synthesis and Analysis of Acetylsalicylic Acid (ASA) (Jan. 12th
to Jan. 13th)
 Determine the concentration of Vinegar.(Jan. 13th to Jan. 14th)
 To be approved for your topic, you must complete the following:
 Develop a detailed procedure (including labeled diagrams of any
laboratory equipment setup).
 Include a list of all required materials and chemicals (include quantities
unless already specified). It is strongly suggested that you use the Internet
and other written references to develop your procedure. ** This initial phase
will be evaluated for communication and thinking and inquiry.
Important Dates:
Procedure and Materials Due Date:
Laboratory Periods:
Wednesday December 17th 2014
Monday, Jan 12th - Tuesday13th or
Tuesday Jan13th - Wed. Jan. 14th
Final Report Due Date:
End of Class on Wed Jan . 14th
NO EXCUSES & NO LATES ACCEPTED
WHAT IS DUE ON Jan 14 th at the start/end of class with no
excuses and no lates accepted:
o Research (typed, in your own words, referenced using
APA and works cited)
o Materials, RE-WRITTEN (modified for YOUR lab)
o Labeled, titled, and referenced diagrams of equipment
o Procedure (RE-WRITTEN for YOUR lab)
o Observation table(s) (titled and neatly written)
o Analysis (neatly written, proper units, organized)
Procedure Notes for the Synthesis and Analysis of Acetylsalicylic Acid
Acetylsalicylic Acid (ASA) is the active component in Aspirin. The benefits of ASA were
first observed by the Chinese in 500 B.C. ASA can be prepared by reacting salicylic acid
with acetic anhydride using very SPECIFIC reaction conditions:
HC7H5O3(s) + C4H6O3(aq)  HC9H7O4(s) + HC2H3O2(aq)
Analysis:
 Determine the limiting reactant in this reaction (density of acetic acid anhydride is
1.0820 g/mL). Calculate the theoretical yield.
 Calculate the percent yield of the ASA.
 Perform an analysis on the purity of your final product. (ex. melting point
determination on Day 2)
 Identify the major sources of error and suggest how you could improve the percent
yield.
Research:
1. Summarize how ASA works in the body (method of action).
2. Discuss uses, benefits and risks of using ASA (cover use in infants, pregnancy,
athletes, adults)
Procedure Notes for Determining the Concentration of a Sample of Vinegar
Vinegar contains approximately 5% acetic acid by volume. You will calculate the exact
concentration of a sample of 10.0 mL of vinegar by performing a titration with a standard
solution of sodium hydroxide. Based on the theoretical molar concentration of the
vinegar, determine the concentration of sodium hydroxide needed for the titration and an
appropriate indicator to use. This experiment must be performed three times to determine
an average.
Analysis:
 Determine the balanced chemical equation for this reaction
 Determine the theoretical molar concentration of acetic acid. (mol/L) Density of
vinegar is 1.01g/mL.
 Calculate the concentration of the vinegar for each trial and the average concentration
of the vinegar. (mol/L)
 Find the % error of the concentration average.
 Identify the major sources of error in this experiment and suggest how you could
improve the experiment to obtain greater precision.
Research:
1. Research how vinegar is prepared from a specific foodstock.
2. Why is vinegar used to preserve pickles and other foods?