Chemical Equations

1
Chemical Equations

• Reactants
• Products

2
Chemical Reaction

• chemical reaction
• is the process by which one or more substances
  change into one or more new substances.
• Reactants
• the original substances in a chemical reaction.
• Products
• the substances that are created in a chemical
  reaction.

Reactants ? Products
3
Chemical Reaction Versus Physical Change

• chemical change
• new substance forms with properties that differ
  from original substance
• physical change
• changes of state of matter

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A chemical equation vsWord Equation

• Word Equation
• methane oxygen ? carbon dioxide water
• ---------------------------------------------
• Chemical Equation
• ?CH4 ?O2 ? ?CO2 ?H2O

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Equations and Reaction Information

• (s) Solid
• (l) Liquid
• (g) Gas
• (aq) Aqueous (dissolved in water)
• ? Yields
• Reversible reactions
• Clip

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Balancing Equations

• Conservation of mass
• The amount and type of atoms starting a reaction
  must be the same as the amount and type of atoms
  after the reaction

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Balancing Equations

• coefficient
• multiplies the number of atoms of each element in
  the formula that follows.
• H2O 2 hydrogen atoms, 1 oxygen atom
• 2H2O 4 hydrogen atoms, 2 oxygen atoms

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Diatomic Elements

• Elements that when found free in nature are 2
  atoms bonded together
• H2, N2, O2, F2, Cl2, Br2, and I2
• Can have other subscripts when in compounds but
  not when alone

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• H2O CO2 -----gt C6H12O6 O2
• Na NaNO3 ---gt Na2O N2

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Assignment

• Practice Problems
• Pgs
• 269
• 271
• 273