Stoichiometry

• Chemical Equation


  Depicts the kind of reactants and products and their relative amounts in a reaction
• Chemical Equation


  • The numbers in the front are called stoichiometric coefficients
  • The letters (s), (g), and (l) are the physical states of compounds
• Because the same atoms are present in a reaction at the beginning (reactants) and at the end (products), the amount of matter in a system does not change
• Law of Conservation of Matter


  An equation must be balanced and have the same number of atoms of the same kind on both sides
• The equation must represent known facts, contain the correct formulas for the reactants and products, and satisfy the law of conservation of mass
• Reactants


  The substances that exist before a chemical change (or reaction) takes place
• Products


  The new substance(s) that are formed during the chemical changes
• Word Equation


  Describes chemical change using the names of the reactants and products
• Word Equation


  • methane + oxygen → carbon dioxide + water
• Unbalanced Equation


  An equation where the number of atoms of each element as a reactant is not equal to the number of atoms of that element as a product
• Balanced Equation


  An equation where the number of atoms of each element as a reactant is equal to the number of atoms of that element as a product
• Balancing Chemical Equations


  1. Write the word equation

  2. Determine the coefficients that make the equation balance

  3. Write the correct formulas for all reactants and products

  4. Write the final balanced chemical equation
• Types of Chemical Reactions

  • Synthesis or Combination Reaction
  • Decomposition Reaction
  • Single-replacement Reaction
  • Double-replacement Reaction
  • Neutralization Reaction
  • Combustion Reaction
• Synthesis or Combination Reaction


  A + B → AB
• Decomposition Reaction


  AB → A + B
• Single-replacement Reaction


  A + BC → AC + B
• Double-replacement Reaction


  AB + CD → AD + CB
• Neutralization Reaction


  HX + BOH → BX + H2O
• Combustion Reaction


  (CH)n + O2 → n CO2 + H2O