WRITING EQUATIONS FOR CHEMICAL REACTIONS

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WRITING EQUATIONS FOR CHEMICAL REACTIONS

• By Mrs. Withers

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WHAT ARE CHEMICAL REACTIONS?

• One or more beginning REACTANTS that combine to
  form
• One or more ending PRODUCTS

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WHAT IS A CHEMICAL EQUATION?

• A sentence with the REACTANTS on the left,
• a YIELD (arrow) in the middle,
• and the PRODUCTS on the right.
• Separate two reactants or two products with a
  PLUS ( ).

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WHAT IS A SKELETON EQUATION?

• Skeleton equations do NOT indicate the relative
  amounts of reactants and products.

Chemistry is EASY
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RULES FOR WRITING SKELETON EQUATIONS

• Write correct formulas for reactants (place these
  on the left).
• Separate reactants with plus sign(s) ().
• Place a yield (arrow) after the last reactant.
• Write correct formulas for products (place these
  on the right).
• Separate products with plus sign(s) ().
• Write diatomic elements as the symbol with a
  subscript of 2.(these elements cannot exist
  alone.)

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WHAT IS A BALANCED EQUATION?

• An equation with the same number of atoms of each
  element on the reactant and the product side.
• COEFFICIENTS (big numbers in front of a formula)
  are used to balance an equation.
• If possible count polyatomic ions as 1 unit
• DO NOT CHANGE SUBSCRIPTS to balance an equation.
• Make sure all coefficients are in the LOWEST
  RATIO.

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NAME FIVE TYPES OF CHEMICAL EQUATIONS.

• COMBINATION OR SYNTHESIS REACTION
• DECOMPOSITION REACTION
• SINGLE REPLACEMENT or SINGLE DISPLACEMENT
  REACTION
• DOUBLE REPLACEMENT or DOUBLE DISPLACEMENT
  REACTION.
• COMBUSTION REACTION

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HOW CAN YOU RECOGNIZE A COMBINATION (SYNTHESIS)
REACTION?

• (WHAT FORM DOES THIS TYPE OF REACTION TAKE?)
• COMBINATION or SYNTHESIS REACTION
• 2 REACTANTS 1 PRODUCT

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HOW CAN YOU RECOGNIZE A DECOMPOSITION REACTION?

• (WHAT FORM DOES THIS TYPE OF REACTION TAKE?)
• DECOMPOSITION REACTION
• 1 REACTANT 2 PRODUCTS

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HOW CAN YOU RECOGNIZE A SINGLE REPLACEMENT
REACTION?

• (WHAT FORM DOES THIS TYPE OF REACTION TAKE?)
• SINGLE REPLACEMENT OR
• (SINGLE DISPLACEMENT REACTION)
• ELEMENT COMPOUND YIELDS ELEMENT COMPOUND

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HOW CAN YOU RECOGNIZE A DOUBLE REPLACEMENT
REACTION?

• (WHAT FORM DOES THIS TYPE OF REACTION TAKE?)
• DOUBLE REPLACEMENT OR
• (DOUBLE DISPLACEMENT REACTION)
• COMPOUND COMPOUND YIELDS COMPOUND COMPOUND

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HOW CAN YOU RECOGNIZE A COMBUSTION REACTION?

• (WHAT FORM DOES THIS TYPE OF REACTION TAKE?)
• COMBUSTION REACTION
• Hydrocarbon OXYGEN as reactants
• YIELD
• CARBON DIOXIDE WATER as products

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NOW YOU NEED TO PRACTICE

• WRITE SOME EQUATIONS
• BALANCE THEM
• IDENTIFY THE TYPE OF REACTION
• DO THIS AGAIN AND AGAIN

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AFTER YOU PRACTICE

• COLLECT YOUR A
• SMILE A MILE