Chemical Reactions

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Chemical Reactions

• The fun stuff!

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Indicators of Chemical Reactions

1. Color Change
2. Formation of a precipitate (two liquids form a
   solid)
3. Formation of a new gas (bubbling, fizzing)
4. Temperature change (without adding or taking away
   heat)
5. Explosions, flames, light or sound
6. Odor change

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Symbols used

• Catalyst a substance that causes or accelerates
  a chemical reaction without itself being
  affected.
• The chemical is not used in the reaction
• Noted above the arrow(s)

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• Heat/Delta symbol (triangle) a symbol of heat or
  delta above the arrow(s) indicates that heat is
  needed for the reaction to occur

5

• Forward arrow chemical reaction only processes
  in one direction. It cannot be reversed
• Double arrow reaction is a reversible reaction
  and can process in either direction

6

• (aq) the substance is aqueous. Means the
  substance is dissolved in water
• (s or ?) the substance is a solid
• (l) the substance is a liquid
• (g or ?) the substance is a gas

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• Word equations are used to describe a reaction
  happening. The description should include
  amounts, states and chemicals. Describing
  equations need to include all the information
  that is possible to describe the reaction.

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Symbolic Equation

• Symbolic equations are written so that a chemist
  can read the reaction in a short abbreviated
  format. Symbolic equations tell as much as a word
  equation does but uses only symbols.

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Symbol to word equations

• When writing word equations
• Include all information possible
• States, amounts, catalyst
• Tell how the reaction is happening

10
Word to symbol equations

• Make sure every word that is written is shown as
  a symbol
• Excluding words that arent important like
  of,to,are, etc

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Naming is still important

• Knowing how to name is still important. Not
  knowing the vocabulary of chemistry will inhibit
  your ability to speak the language of chemistry.