Interactive Chemistry Worksheets for Students

 

Periodic table

Naming compounds

Basic formula

Simple compounds

Ionic compounds 1

Ionic compounds 2

Chemical suffixes

Old chemical names

Hydrocarbons - Alkanes

Alkanes, alkenes & alkynes

Alkanols to alkanoic acids

 

Common compounds

Common formula quiz

Acids, bases and salts

Covalent compounds

Printable worksheets
 

 

 

A precipitation reaction is a reaction in which two solutions are mixed to produce an insoluble solid called a precipitate.

Simplified Solubility Rules :If a compound contains one of the following chemicals it is always soluble

  • A Group I element. Eg. Sodium, Na+ or potassium, K+
  • An ammonium group, NH4+
  • A nitrate group, NO3-
  • An acetate group, CH3COO-

 

Physical states
(aq) = aqueous and (s) = solid

Student Instructions

  • Complete the word equation for each precipitation reaction.
  • Write a balanced equation for each reaction. Use the valencies below to help you.

Valency 1

Valency 2

Sodium Na+, potassium K+, silver Ag+,
Iodide I-, nitrate NO3- group,  OH- group

Mercury Hg2+, Copper Cu2+, Lead Pb2+
Sulfate group SO42-

  • Include physical states(aq) or (s) in your chemical equation.
  • Use the simplified solubility rules to determine the solid precipitate

 

1. Sodium hydroxide + silver nitrate sodium nitrate +  silver hydroxide (brown)

NaOH(aq) + AgNO3(aq) NaNO3(aq) + AgOH(s)

 

2. Sodium hydroxide + copper sulfate sodium sulfate + copper hydroxide (blue)

2NaOH(aq) + CuSO4(aq) Na2SO4(aq) + Cu(OH)2(aq)

 

3. Potassium iodide + lead nitrate potassium nitrate + lead iodide (yellow)

2KI(aq) + Pb(NO3)2(aq) 2KNO3(aq) + PbI2(s)

 

4. Potassium iodide + mercury nitrate mercury iodide (orange) + potassium nitrate

2KI(aq) + Hg(NO3)2(aq) HgI2(s) + KNO3(aq)

 

5. Potassium iodide + silver nitrate potassium nitrate + silver iodide (white/ yellow)

KI(aq) + AgNO3(aq) KNO3(aq) + AgI(s)

 

6. Sodium chloride + silver nitrate sodium nitrate + silver chloride (white)

NaCl(aq) + AgNO3(aq) NaNO3(aq) + AgCl(s)

 

7. Mercury nitrate  + potassium fluoride mercury fluoride + potassium nitate

Hg(NO3)2(aq) + 2KF(aq) HgF2(aq) + 2KNO3(aq)

 

8. Copper sulfate + potassium iodide copper(II) iodide + potassium sulfate

CuSO4(aq) + 2KI(aq) CuI2(s) + K2SO4(aq)

Note: The above reaction is more complex. Copper(I) iodide, CuI is formed with iodine, I2(aq)

This equation is technically correct. 2CuSO4(aq) + 4KI(aq) 2CuI(s) + 2K2SO4(aq) + I2(aq) (overall brown/ red)

The iodine ions reduce the copper(II) ions to copper(I).