Chemical Equations & Reactions

• A chemical reaction is also described by a balanced equation in which each side of the equation has the same number of atoms of each element and mass is conserved.
• Equation. Describes a chemical change, a representation of a chemical reaction
• Symbols used in Chemical Equation:

  ·        The states of the reactants

  ·        The states of the products

  ·        The reaction conditions
• Arrangement in Balancing Chemical Equations

  ·        Metal

  ·        Nonmetal

  ·        Hydrogen

  ·        Oxygen
• Chemical Reaction. A process in which one or more substances, the reactants are converted to one or more different substances, the products
• Chemical Reaction. Substances are either chemical element or compound
• REACTANTS are converted to PRODUCTS and the process is symbolized by a chemical equation.
• The plus sign indicates that iron reacts with sulfur. The arrow signifies that the reaction “Forms” or “Yields”
• Combination Reaction. Also known as Synthesis reaction, is a reaction in which two or more substances combine to form a single substance.
• Combination Reaction. General Form: A + B → AB
• Decomposition Reactions. Is a reaction in which a compound breaks down into two or more simpler substances
• Decomposition Reactions. General Form: AB → A + B
• Single-Replacement Reactions. A reaction in which one element replaces a similar element in a compound
• Single-Replacement Reactions. General Form: A + BC → AC + B
• Combustion Reaction. A reaction in which a substance reacts with oxygen gas, releasing energy in the form of light and heat
• Combustion Reaction. Combustion reactions must involve O2 as one reactant
• Combustion Reaction. The combustion of hydrogen gas produces water vapor
• Double Replacement Reactions. A reaction in which the positive and negative ions of two ionic compounds exchange places to form two new compounds
• Double Replacement Reactions. General Form: AB + CD → AD + CB
• Balancing chemical equations is important because it gives a more accurate representation of what's happening in a reaction, and the accuracy of the ratios of moles is important in calculating the theoretical yield and how much stuff is reacting mass-wise.
• The purpose of balancing chemical equations is to make both sides of the reaction, the reactants, and the products, equal in the number of atoms per element. This is achieved by changing the coefficients of the compounds.
• Chemical Equation describes a chemical change, a representation of a chemical reaction.