Aqueous Reactions
and
Solution Stoichiometry



Procedures for writing net ionic equations:

  1. Write a balanced equation.
  2. Break down the formulas in the equation into ions if they are soluble.
  3. Ions that appear in identical forms among both the reactants & products are called spectator ions - cross off/cancel out.
  4. Ions left after spectator ions are crossed off will be the components of the net ionic equation.
  5. Be sure the charges of the ions are the same on both sides and the number of atoms are the same.

Acids

  1. that are able to ionize in aqueous solution to form H+
  2. often called proton donors
  3. Monoprotic acids - give one hydrogen ion per molecule of acid
  4. Diprotic acid - can give two hydrogen ions and occurs in two steps

Bases

  1. Substances that accept hydrogen ions
  2. Any substance that increases the concentration of hydroxide ions when added to water
*Page 115 is a table of strong acids and bases - must KNOW

Neutralization

  1. When acids and bases are mixed, a neutralization reaction occurs in which water and a salt are produced
  2. Salt - any ionic compound that has the cation from the base and the anion from the acid

Oxidation-Reducation Reactions

  1. Precipitation reaction - cations and anions come together to form an insoluble.
  2. Neutralization reaction - hydrogen ions and hydroxide ions come together to form water molecules.
  3. Oxidation-reduction reaction -transfer of electrons between ions
  4. Oxidation - when an atom, ion, or molecule becomes more positively charged (loses electrons).
  5. Reducation - when an atom, ion, or molecule becomes more negative (gains electrons).

General Rules for oxidation-reduction reaction

  1. Single elements have an oxidation of zero.
  2. Alkali metals are always +1.
  3. Alkaline earth metals are always +2.
  4. Fluorine and most other halogens are -1.
  5. Oxygen is usually -2 except when with fluorine and if it is a peroxide.
  6. Nonmetals usually have negative values.
  7. Hydrogen is +1 when bonded with nonmetals.
  8. All oxidation numbers in a compound must equal zero.
  9. The sum of the oxidation numbers in a polyatomic ion must equal the charge of the ion.

Concentration of Solutions

Concentration designates the amount of solute dissolved in a given amount of solvent (the more solute in a certain amount of solvent the more concentrated).

Titrations

Titrations are used to determine the concentration of unknown acids or bases using a known molarity of acid or base (standard solution = known solution).

Laboratory Work

  1. Solubility and Solutions - Sept. 14-15
  2. Oxidation-Reduction Reactions - Sept. 19-20
  3. Acid-Base Titrations - Sept. 22

Test

Test Review