Identification of Ionic Solutions
This week’s laboratory assignment will help you:
practice equation writing and balancing
find properties of compounds in
The CRC Handbook of Chemistry and Physics
identify the products formed in a set of double replacement reactions, and
use the identities of those products to identify the reactants.
Be sure to complete the prelaboratory exercises before coming to lab. The
CRC Handbook of
Chemistry and Physics
lists the physical properties of inorganic compounds in an extensive table.
Organized alphabetically, the table gives the color and crystal form of solids, melting and boiling
. Look up each of your predicted nonelectrolyte or weak electrolyte
products, and record the properties that will help you identify them, such as the color and
expected appearance of each precipitate. These product predictions will guide your later
reasoning, leading to the correct identification of the unknown ionic solutions. Do not assume
that the order of the reactions on the prelaboratory assignment indicates the actual order of your
Use deionized water from a wash bottle for the final rinse because tap water will
contaminate your glassware with dissolved minerals and confound your results.
wash your hands and arms thoroughly as you leave the lab today. Wipe up any spilled chemicals
with a wet paper towel and discard it in the wastebasket. Rinse your spot plate over the waste
bottle, not into the sinks.
Table 1. Solubility of some ionic compounds in water
Compounds containing ammonium (NH
) or any Group 1 (IA) cation.
Compounds containing nitrate (NO
) or acetate (CH
Soluble with few exceptions:
Compounds containing chloride, bromide, or iodide (Cl
) ions. Insoluble if
combined with silver, lead(II), or mercury(I) (Ag
Compounds containing sulfate (SO
). Insoluble with barium or lead(II) (Ba
Insoluble (unless covered by rule I.A.)
chromate or dichromate (OH
*Carbonic acid, once formed in aqueous solution, rapidly decomposes into water and