Laboratory
The Rules of Solubility
Name:__________________
Date:___________
Purpose:
1) Research and organize data on solubility and color change properties, used in qualitative analysis.
2) Determine the presence or absence of ions in unknown solutions.
Directions:
(1)
Use a computer, the MERC index, or the CRC handbook to research the color of the
chemical solutions listed below. Then, construct a table called “Table of Knowns”. The
chemical formulas for each chemical solution (below) should be listed down the side and
across the top.
List of Chemical Solutions: Barium Chloride, Copper (II) Nitrate, Copper (II) Sulfate,
Potassium Chloride, Potassium Chromate, Potassium Sulfate, Silver Nitrate
(2)
(3)
(4)
(5)
(6)
Fill in the rest of the table for the products that will be made when you mix two of the
chemicals together. (Only half of the table needs to be filled in, otherwise you’ll be writing
identical information in the other half.) Research the colors and solubility of the chemicals
and write your findings in each box. You will need to use this information to clearly
identify unknown substances, so be specific. This research needs to appear in your lab
notebook!
When your table is completely filled in, check with your instructor, and make an identical
table as above to fill in using laboratory experiment observations, except instead of putting
in the formula names, label the top and sides with the letters A through G. Give this table a
title.
Each of the chemicals listed above are labeled A, B, C, D, E, F, or G, on their container.
Your task is to figure out what chemicals they are. (e.g. A is Barium Chloride – it’s not
really, this is just an example)
Use a well-plate to mix the various chemicals together. By making observations of the
properties and products produced, figure out the chemicals corresponding to the letters on
the containers. MAKE SURE YOU TAKE THOROUGH OBSERVATIONS. This is your
laboratory data.
Write your lab report as usual. There will be no math, but include a net ionic equation for
each precipitate observed for your calculations section. You will need a conclusion for each
unknown, with at least two pieces of evidence for each. In your conclusions, refer to
chemical names or formulas; do not make vague references to the letters A, B, C, etc. In
your discussion, TALK ABOUT PARTICLES. What is happening between the water and
the ions in a solution and when a precipitate forms? Be specific, refer to data and
observations. DRAW A MODEL to represent the particles in this lab. You do not need to
do an error section.