AP Chemistry Precipitate Lab
Purpose: In this lab you will test the prepared solutions with each other for evidence of a double replacement
(metathesis) reaction.
Pre-Lab Questions.
Answer with complete sentences on a separate piece of paper, labeling it well and skipping lines, and use ink
or type.
1. What are the steps to prepare 1liter of a 1 molar solution from any salt? Be specific.
2. Specifically, how would your steps change if you wanted 1.75 liters of the one molar solution?
3. What is the formula to calculate the amount of concentrated liquid solute needed to make a more dilute
solution?
4. According to the calculation in question 3, you need only 12 mL of the concentrated solution. What
steps would you do to make this into 0.750 L of dilute solution? Be specific.
5. What are the three products that would cause a double replacement reaction to occur (be the driving
force)?
Safety: Use goggles and apron at all times. Wash your hands thoroughly after handling chemical supplies!
Materials:
Silver Nitrate
Sodium Sulfate
Bismuth(III) Nitrate
Barium Nitrate
Lead(II) Nitrate
Hydrochloric Acid
Potassium Dichromate
Sodium Hydroxide
Sodium Chloride
Potassium Iodide
Sodium Sulfide
Pipets
11 small test tubes
Test tube rack
Labeling tape or Pencil
Plastic sheets
Procedures:
1. Prepare 2 spotting tables (at home).
2. Place a sample of each prepared solution into a marked test tube.
3. Place the plastic sheet over one of your prepared spotting tables.
4. Place one drop of each solution in the appropriate place of the spotting table.
5. Note any changes on the second spotting table. For example, note the appearance and color of any solids
that form, including the tone of the solid (bright white versus faint white, etc) or the formation of bubbles,
or both.
Clean-up and disposal:
Most solids formed in this lab are hazardous to the water system. Please pick up the corners of the plastic sheet,
dumping the liquid into the marked waste container and then throw the sheet away in the trash. Unused solutions
should be poured into the disposal container set up by your teacher, with the empty pipets thrown away. Clean up
your lab area and replace the lab equipment.
Data and Conclusions:
Place a pretty copy of your spotting table with results (observation) into your lab report.
For each square of your spotting table that formed a solid or bubbles, write out the balanced chemical reaction and
net ionic reaction for that square on a separate piece of paper, labeling it well and skipping lines. You may use
pencil.
Post-Lab Questions.
Answer with complete sentences on a separate piece of paper, labeling it well and skipping lines, and use ink
or type.
1. Why could you not write a net ionic equation for the reactions that did not produce a solid, water, or gas?
2. Only one reaction in your table would have produced water (HOH). Which reaction is it?