1. Describing chemical reactions

• reactants----- yield----> products
  i.e. NaOH + HCl -------> NaCl + HOH
• always in a predictable manner
• always conserve mass / matter / number of atoms

2. Balancing chemical equations

• a balanced chemical equation has the same number of atoms on both sides of the equation
• "how to" tips
  • start by evaluating the equation
  • look for the simple / single atom or element compounds
  • work back and forth across the equation fixing one element at a time
  • there is a lot of guess and check
• a web site with instructions here
• a second web site with instructions here
• some practice problems and answers here

3. Types of chemical reactions :,,

• synthesis
  • A +B ----> AB
  • building a new compound
• decomposition
  • AB -----> A+B
  • destruction of a compound
• single displacement
  • A + BC----> AC + B
  • replacement can be predicted by location on table
• double displacement
  • AB + CD ------> AD + CB

4. Energy and reactions

• endo / exothermic reactions
• effects of catalysts and inhibitors

5. need to see more? helpful web sites:

study guide and defintiions thanks to ryan gibbons

Chem4Kids:Reactions

Chem4Kids:Math:Formulas

Chem4Kids:Math:symbols

Chem4Kids:Math:Units

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