Honors
SOLUBILITY LAB
Prelab: In the introduction for your lab report, include a definition of solubility, lattice energy and a brief
description of how the size and charge of the ions in an ionic compound affect both solubility and
lattice energy.
Goals: (1) To systematically combine ten aqueous solutions and record any chemical changes.
(2) To identify your assigned unknown
(3) To write net ionic equations for all of the observed chemical reactions.
(4) To formulate some general solubility rules based on experimental observations.
Safety: Several of these compounds are toxic. Please be sure to wash your hands at the conclusion of the lab
and ABSOLUTELY NO NAKED EYEBALLS PERMITTED!!! If you can’t be bothered to keep your
goggles on, I can’t be bothered to give you a grade for doing the lab.
Procedure:
1. Clean a twelve-well tray and rinse well (soap will react with some of the solutions).
2. Clean the plastic pipets with several changes of tap water.
3. Go to Reagent Central and get a sample of each solution (fill the wells about ¾ full). BE SURE TO
WRITE DOWN WHAT SOLUTION YOU’RE PUTTING IN EACH WELL!!!
4. Binary mix the ten solutions (e.g. 1 drop of solution A and 1 drop of solution B) using the reaction
matrix chart as a guide. Use a clean stirring rod to mix the drops if necessary. If you think you’ve mixed
up your pipets, rinse them out before using.
Caution: Drop the drops – do not touch the solution on the plastic with the tip of the pipet
or you will contaminate everything!
5. Devise an accurate code to describe any precipitates (they’ll be cloudy or look like a gel) that you see.
(e.g. ‘bird dropping white’ not just ‘white precipitate’) One of the reactions will make bubbles.
6. When you and your lab partners are satisfied that all of the ‘No Reaction’ spots really don’t have a
reaction (and there are some), rinse the solutions in the 12 well tray down the drain, clean off the sheet
protector and rinse out the pipets with water. (DO NOT throw the pipets away!)
Data
1. Include your reaction matrix with your lab report. Include a key to your code for the reaction
observations.
2. For every precipitate forming reaction that you observed, write a balanced net ionic chemical equation
(there should be about ~20 reactions producing a precipitate).
Discussion
(1) In your discussion section, use your observed reactions to formulate some general solubility rules. For
example, we’re starting with sodium salts of a lot of compounds so it would appear that compounds with
sodium cations have a high solubility. Look at which cations and anions produced the most precipitates…this
will help guide you in formulating your solubility rules. DO NOT include solubility rules for compounds that
you did not observe. For example, don’t include the fact that mercury(I) and silver form insoluble chlorides
because you personally did not observe this fact. (2) Identify your unknown and indicate what reaction
confirmed your conclusion.
Conclusion
In your conclusion section, include a list of your solubility rules. Also include the identity and unknown number
of your unknown.
Be sure to provide a peer review for your group members.
Honors
Solubility Lab Rubric
Cover page: your name underlined and names of group members: 1 pt
Section Headings: 5 pts
Introduction: (6 pts total)
 Definition of solubility, lattice energy and a brief description of how the size and charge of the ions in an
ionic compound affect both solubility and lattice energy. (3 pts)
 Experimental objectives included in the last few sentences of the introduction. (3 pts)
Procedure: (10 pts total)
 Paraphrased (-5 pts if copy from lab sheet)
 Paragraph form: (5 pts)
Data: 20 net ionic equations (can be attached to report and hand written) (30 pts total)
 -5 pts correct products, but chemical formulas are written incorrectly
 -10 pts 10% to 50% of than half of the products are incorrect (not the ppts)
 -15 pts more than 50% of the products are incorrect
 -30 pts no NIE
Results/Discussion: (9 pts total)
 Identify unknown with justification of choice (2 pts)
 Minimum of two sources of error related to identification of your unknown (2 pts)
 General solubility rules based on your experimental observations (5 pts)
 -3 pts if solubility rules contain substances not included in this experiment (e.g. mercury compounds)
Conclusion: (5 pts total)
 Restate experimental objectives (2 pts)
 Identify unknown (1 pt)
 Include general solubility rules that you observed (2 pts)
Peer evaluation: (5 pts)
 5 = fantastic, 1 = abysmal
 -5 pts from your lab grade if omitted