Solubility

• What precipitate forms when sodium chromate is added to silver nitrate solution?

  A red precipitate of silver chromate
• What are the solubility statuses of the following substances: sodium chloride, lead nitrate, calcium sulfate, potassium hydroxide, silver chloride, calcium carbonate, and ammonium carbonate?

  • Soluble: Sodium chloride, lead nitrate, potassium hydroxide, ammonium carbonate
  • Insoluble: Calcium sulfate, silver chloride, calcium carbonate
• What is a solubility rule for lead compounds?

  Lead compounds are generally insoluble in water, except for lead nitrate.
• What is the purpose of the reaction between sodium chromate and silver nitrate?

  It is used to stain nerve cells for viewing under a microscope.
• What is a precipitation reaction?

  • A reaction where soluble substances in solutions cause an insoluble precipitate to form.
  • Example: Formation of silver chromate from sodium chromate and silver nitrate.
• What are the general rules for solubility in water?

  • Soluble: All common sodium, potassium, and ammonium salts; all nitrates; most chlorides; most sulfates; sodium, potassium, and ammonium carbonates; sodium, potassium, and ammonium hydroxides.
  • Insoluble: Silver, lead chlorides; lead, barium, calcium sulfates; most carbonates; most hydroxides.
• What happens when lead nitrate and sodium chloride react?

  They form soluble sodium nitrate and a white precipitate of lead chloride.
• What is the balanced equation for the reaction between lead nitrate and sodium chloride?

  Pb(NO_3)_2(aq) + 2NaCl(aq) → PbCl_2(s) + 2NaNO_3(aq)
• What is the test for carbon dioxide using limewater?

  It is a precipitation reaction that forms insoluble calcium carbonate.
• What is the ionic equation for the formation of lead chloride?

  Pb^{2+}(aq) + 2Cl^{-}(aq) → PbCl_2(s)
• How do ionic equations show the formation of precipitates?

  • They show the ions that react to form the precipitate.
  • Spectator ions do not change and are not included in the ionic equation.
• What happens when two solutions containing soluble salts react together?

  The ions from the salts swap, potentially forming a precipitate.
• What is the word equation for the reaction between copper sulfate and potassium carbonate?

  Copper sulfate + Potassium carbonate → Copper carbonate + Potassium sulfate
• Why does potassium sulfate not form a precipitate in the reaction with copper sulfate?

  Because all potassium salts are soluble.
• What is the ionic equation for the formation of copper carbonate?

  Cu^{2+}(aq) + CO_3^{2-}(aq) → CuCO_3(s)
• How can a pure, dry sample of an insoluble salt be prepared from two soluble salts?

  1. Wear eye protection.
  2. Mix the two solutions in a beaker.
  3. Filter the mixture.
  4. Rinse the beaker with distilled water and pour through the funnel.
  5. Pour distilled water over the precipitate.
  6. Remove the filter paper and dry it in a warm oven.
• Why is the beaker rinsed with distilled water during the preparation of an insoluble salt?

  To ensure all the soluble salt is washed into the funnel.
• Why is distilled water poured over the precipitate in the funnel?

  To wash away any remaining soluble impurities.
• Suggest two other ways of drying the precipitate.

  Using a desiccator or air drying.
• What is the predicted name of the precipitate when magnesium sulfate reacts with barium chloride?

  Barium sulfate
• What is the balanced equation for the reaction between magnesium sulfate and barium chloride?

  MgSO_4(aq) + BaCl_2(aq) → BaSO_4(s) + MgCl_2(aq)
• What is the ionic equation for the reaction between magnesium sulfate and barium chloride?

  Ba^{2+}(aq) + SO_4^{2-}(aq) → BaSO_4(s)
• What is the predicted name of the precipitate when sodium chloride is added to copper nitrate?

  Copper chloride
• Why does sodium chloride produce a precipitate when added to copper nitrate?

  Because copper chloride is insoluble in water.
• What are the combinations of aqueous solutions that can produce a precipitate from the given solutions: sodium carbonate, copper sulfate, and barium chloride?

  • Sodium carbonate + Copper sulfate → Copper carbonate (precipitate)
  • Barium chloride + Sodium carbonate → Barium carbonate (precipitate)
• What is the ionic equation for the reaction between sodium carbonate and copper sulfate?

  Cu^{2+}(aq) + CO_3^{2-}(aq) → CuCO_3(s)
• What is the ionic equation for the reaction between barium chloride and sodium carbonate?

  Ba^{2+}(aq) + CO_3^{2-}(aq) → BaCO_3(s)