This document discusses precipitation reactions and salt families. It provides the following key points: 1. Salts are produced from chemical reactions between acids and other substances. Each acid produces a characteristic family of salts, such as sulfates from sulfuric acid and nitrates from nitric acid. 2. Precipitation occurs when two solutions are mixed and an insoluble compound forms, coming out of solution as a solid precipitate. Solubility rules can be used to predict whether a precipitation reaction will occur. 3. Practical experiments are described to mix solutions of substances like lead nitrate and barium chloride and observe any precipitates that form based on the solubility rules. Word equations are also written for precipitation

1. PRECIPITATION
REACTIONS
10 Chemistry

2. Salt Families
Salts are produced by chemical reactions involving acids.
Each acid has its own family of salts
• Sulfuric acid produces sulfates
• Nitric acid produces nitrates
• Hydrochloric acid produces chlorides
• Carbonic acid (very weak) produces carbonates.

3. ACID SALT
Sulfuric acid Copper sulfate
Iron sulfate
Zinc sulfate
Nitric acid Zinc nitrate
Calcium nitrate
Sodium nitrate
Hydrochloric acid Sodium chloride
Iron chloride
Potassium chloride

4. Solubility Rules
1. All sodium compounds are soluble.
2. All nitrates are soluble in water
3. All chlorides and iodides are soluble except
for silver chloride/iodide and lead
chloride/iodide
4. All sulfates are soluble except for barium
sulfate and lead sulfate.
5. All carbonates are insoluble except for sodium
and potassium which are soluble.

5. Precipitation is
the reverse of
the dissolving
process….an
example

6. A precipitation reaction

7. Lead nitrate Potassium
solution iodide
solution When the two solutions
are mixed, the lead
and iodide come
Pb2+ I- together as a solid.
- K+
NO3
-
Pb2+ I
The solution K+
The solution
contains
contains NO3-
potassium
lead ions
and iodide
and nitrate
ions. Lead iodide is insoluble
ions.
and precipitates from
Potassium
Lead nitrate solution.
iodide is

8. Writing word equations for precipitation
reactions
Lead nitrate + potassium iodide-->lead iodide + potassium nitrate
Swap the names around and if one of the products is
insoluble a precipitate will form.
The subscript (aq) means aqueous solution, the subscript
(s) means a solid precipitate.
Lead nitrate(aq) + potassium iodide(aq)-->lead iodide(s) + potassium nitrate(aq)

9. Use the solubility rules to predict whether there will be a
precipitate, or only soluble products.
Write the word equation for each reaction:
Lead nitrate Barium
chloride
Sodium Precipitate, Precipitate,
carbonate lead carbonate barium carbonate
Sodium Precipitate, No precipitate
chloride lead chloride
Sodium sulfate Precipitate, lead Precipitate, barium
sulfate sulfate

10. Word Equations
Sodium carbonate(aq) + Lead nitrate(aq)-> sodium nitrate(aq) + lead carbonate(s)
Sodium chloride(aq) + Lead nitrate(aq)-> sodium nitrate(aq) + lead chloride(s)
Sodium sulfate(aq) + Lead nitrate(aq)-> sodium nitrate(aq) + lead sulfate(s)
Sodium carbonate(aq) + Barium chloride(aq)-> sodium chloride(aq) + Barium
carbonate(s)
Sodium chloride(aq) + Barium chloride(aq)-> sodium chloride(aq) + Barium
chloride(aq)
Sodium sulfate(aq) + Barium chloride(aq)-> sodium chloride(aq) + Barium sulfate(s

11. PRACTICAL- In a test tube mix small quantities of two
solutions and note whether there is a precipitate or not, and
if so its colour..
Lead nitrate Barium chloride
Sodium
carbonate
Sodium chloride
Sodium sulfate

12. PRACTICAL- In a test tube mix small quantities of two
solutions and note whether there is a precipitate or not, and
if so its colour..
Lead nitrate Barium chloride
Sodium
carbonate
Sodium chloride
Sodium sulfate

13. Solubility Rules Remember?
1. All sodium compounds are soluble.
2. All nitrates are soluble in water
3. All chlorides and iodides are soluble except
for silver chloride/iodide and lead
chloride/iodide (PRECIPITATE)
4. All sulfates are soluble except for barium
sulfate and lead sulfate (PRECIPITATE)
5. All carbonates are insoluble (PRECIPITATE)
except for sodium and potassium which are
soluble.

14. PRACTICAL- In a test tube mix small quantities of
two solutions and note whether there is a precipitate
or not ..
Lead nitrate Barium chloride
Sodium White White
carbonate precipitate precipitate
Sodium chloride White No precipitate
precipitate
Sodium sulfate White White
precipitate precipitate

15. TEST REVISION
STUDY!!!

16. Atoms & Ions
• Write electron arrangements 20 Ca40, 20 electrons,
2,8,8,2
• Know names and chemical symbols for first 20
elements.
• Work out the element given, 2,8,6
• Do atoms gain or lose electrons example above
would gain 2 electrons
• Ion formed, what is its charge,
• S2-

17. Atoms and Ions
• Why do atoms gain or lose electrons?
• …trying to get a full outer shell
Some common ions
• Oxide O2-
• Sulfate ion SO42-
• Nitrate ion NO3-
• Hydroxide ion OH-

18. Combustion
• Fuel and air. You need some heat to make combustion
happen. Heat to melt and form vapour, vapour that burns.
• Why does the candle keep burning?
• How do you put fires out?
• Complete and incomplete combustion. Word equations for
methane burning

19. Solubility and Precipitates
You will be given the solubility rules.
• What is meant by a precipitation reaction?
• Identify the insoluble material using the rules
• Why does the precipitate form? …something insoluble is
formed, it has to come out of solution.
• Write a word equation.