Mr. Everett's Web Page

Unit Information
Atomic history and radioactivity corresponds to chapters 8 and 17 in the text Foundations of College Chemistry by Hein and Arena..  Chapter 8 is an introduction to chemical reactions and equations.  Chapter 17 focuses solely on the redox process.
Assignments:
Text Problems Writing Reaction Equations - Solutions
Balancing Equations - Solutions - Which ones are redox? Writing More Reaction Equations - Solutions
Predicting Products - Solutions  
States of Matter
Predicting states of matter from a sentence equation can be difficult, but the clues given below are meant to help you out.
  1. The following are gases at room temperature:
    • Elements − hydrogen, nitrogen, oxygen, fluorine, chlorine
    • ammonia
    • carbon monoxide and carbon dioxide
    • nitrogen monoxide and nitrogen dioxide
    • sulfur dioxide and sulfur trioxide
    • hydrogen-compounds (e.g. hydrogen chloride and hydrogen cyanide)
  2. Acids are aqueous.  Any phrases that refer to being dissolved or in solution means the compound is aqueous.
  3. Liquids − bromine, mercury, and water
  4. All other elements are solids.  When in doubt, so are most other compounds, particularly ionic compounds.
Types of Reactions

1.  Combustion – The reaction of a hydrocarbon with oxygen in the presence of heat to produce carbon dioxide and water vapor. 

  • If the supply of oxygen is limited (incomplete combustion), carbon monoxide is produced instead of carbon dioxide.
  • If the supply of oxygen is sufficient, or in excess (complete combustion), carbon dioxide is produced as stated above.
  • When nothing else is indicated, go with carbon dioxide.

 2.   Synthesis (Direct Combination) – The combination of two or more elements/compounds to produce one compound.

 3.  Decomposition – The breaking down of a compound (frequently with heat or electricity) into its elements or other smaller compounds.

  • Chlorates – decompose into metal chlorides and oxygen.
  • Carbonates – decompose into metal oxides and carbon dioxide

4.  Single Displacement/Replacement – The more “active” metal or halogen takes the place of another metal or halogen in a compound.  The replaced metal or halogen is left in its free state.

  • Always consult an activity series to make sure the reaction works.
  • If the reaction does not work, write “no reaction.”

 5.  Double Displacement/Replacement or Metathesis – The ions of two aqueous compounds switch partners to produce at least one precipitate.

  • Always consult a solubility table to make sure the reaction works.
  • If the reaction does not work, write “no reaction.”

 6.  Oxidation/Reduction – A reaction where one element loses electrons (oxidized) from reactants to products, and another element gains electrons (reduced) from reactants to products.

  • Single displacement and combustion reactions are ALWAYS redox.
  • Reactions involving free elements as either reactants or products are redox. This will include many synthesis and decomposition reactions.
  • Double displacement reactions are NEVER redox.  The charges of the ions do not change when they switch
  • Look for polyatomic ions that have been broken down because they usually contain an element that has been oxidized or reduced.

Home
Site designed and maintained by Mr. Everett.
Last update: Thursday, June 16, 2011