CHEM 211-10 10
Experiment 3 A & B
Title Page: (See Lab Manual Part III. p. 19)
How Does the
pH of Aqueous
H 3 O + Cl -
Na + - OH
H 2 O
The Questions of the Week:
State the Questions of the Week:
1. What can solubility in acidic and/or basic aqueous solutions tell us about structures of organic
State your group’s initial predictions of relative solubilities of the twelve solute compounds in acidic and
basic aqueous solutions compared with their solubilities in water (your claims). Provide the warrants
that led to these claims citing the data on which the warrant is based. Include a brief description of the
experimental plan to answer the QOW.
2. How can we use pH effects on solubility to separate mixtures of compounds
Present your group’s proposal for separating your selected pair of compounds (your claim), the warrant
used to devise your separation protocol and the specific data upon which the warrant is based.
100 words or less, total for both sections.
Summary of Results: (See Lab Manual Part III. pp. 19-20)
Data only: Tables with no text explanations.
Include the following tables:
• A Table of Group Relative Solubility Results.
• A Table summarizing All-Class Results on Relative Solubilities of all solutes in 1M HCl vs. water.
• A Table summarizing All-Class Results on Relative Solubilities of all solutes in 1M NaOH vs. water.
• A Table summarizing All-Class Results of recovery and % recovery of compounds from the separations
of mixtures of two compounds.
Discussion and Conclusions: (See Lab Manual Part III. p. 20)
1. How did the experimental results relate to your original claims on the structural effects on solubility
change with pH What changes did you make in your claims and warrants on acid-base effects on
solubility as a result of the data collected in Part A
2. Comment on the success or lack of success of your group’s separation process in Part B indicating your
criteria for success. How did your group’s recovery results compare with those of other’s in the class
for the same compounds From the all-class data, do the results indicate that some compounds are
recovered or separated more effectively than others How did you judge effectiveness Provide a
warrant that led your group to each of your claims and the specific data used to develop each claim.
Reflection: (See Lab Manual Part III. p. 20)
In this two part experiment you first tested the effects of pH (1M acid vs. 1M base) on the solubility of
organic compounds in water. Then you used your experimental results to devise an extraction protocol to
separate two of the compounds your group tested.
Trace the development of your understanding concerning how acids or bases operate to increase solubility
of organic compounds in water and the relationship between the structure of the solutes and pH effects on
CHEM 212-09 11 Experiment 1: pH vs. Solubility
their water solubility. Finally, what two things did you learn about factors that might affect the success of
acid-base extractions and how did your experience in this experiment lead to this understanding.
Appendix: (See Lab Manual Part III. p. 20)
Include one copy of all handouts for this experiment and all items in the Experiment 3 section of all of your
group members’ Data Binders.
Laboratory Report Due Date:
Your lab report for Experiment 3 is due in your lab period during the week of October 13-19. (See Lab Manual
Part I p. 5.)