Precipitation Reactions: Solid

Formation

Precipitation reactions occur when two soluble ionic

compounds react to form an insoluble solid

(precipitate). These reactions can be predicted by

knowing solubility rules. The driving force for these

reactions is the formation of an insoluble solid.

We will test the following solutions with both silver

nitrate and barium nitrate. The silver and barium

tests are a good way to determine what anions are

present in a solution of an ionic compound.

Sodium Chloride, Sodium Acetate, Sodium

Sulfate, Sodium Carbonate, Sodium Nitrate,

and Sodium Chromate.

Precipitation Reactions 1: Silver Nitrate

Record your observations when adding three drops of silver nitrate solution to a

small amount of each of these solutions in a small test tube.

Write balanced full and net ionic equations for each ch emical reaction

that occurs.

Precipitation Reactions 3: Barium Chloride

Record your observations when adding three drops of silver nitrate solution to a

small amount of each of these solutions in a small test tube.

Write balanced full and net ionic equations for each chemical reaction

that occurs.

Flame Tests

Flame tests are often used to identify cations in soluble ionic compounds. Think

about the vibrant colors you see in fireworks. The same process occurring to

produce color in fireworks is what we will see with flame tests. Many cations give

off characteristic colors when placed in the outer cone of a flame.

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Figure 4.1: Lead nitrate and

sodium iodide are mixed to give a

lead iodide precipitate. This

Wikimedia image is shared under

a CC BY-3.0 license.