Procedures for writing net ionic equations:
Write a balanced equation.
- Break down the formulas in the equation into ions if they are soluble.
- Ions that appear in identical forms among both the reactants & products are called spectator ions - cross off/cancel out.
- Ions left after spectator ions are crossed off will be the components of the net ionic equation.
- Be sure the charges of the ions are the same on both sides and the number of atoms are the same.
- that are able to ionize in aqueous solution to form H+
- often called proton donors
- Monoprotic acids - give one hydrogen ion per molecule of acid
- Diprotic acid - can give two hydrogen ions and occurs in two steps
- Substances that accept hydrogen ions
- Any substance that increases the concentration of hydroxide ions when added to water
- Any acid or base that is a strong electrolyte is a strong acid or base
*Page 115 is a table of strong acids and bases - must KNOW
- Any acid or base that is a weak electrolyte is a weak acid or base
- When acids and bases are mixed, a neutralization reaction occurs in which water and a salt are produced
- Salt - any ionic compound that has the cation from the base and the anion from the acid
- Precipitation reaction - cations and anions come together to form an insoluble.
- Neutralization reaction - hydrogen ions and hydroxide ions come together to form water molecules.
- Oxidation-reduction reaction -transfer of electrons between ions
- Oxidation - when an atom, ion, or molecule becomes more positively charged (loses electrons).
- Reducation - when an atom, ion, or molecule becomes more negative (gains electrons).
General Rules for oxidation-reduction reaction
- Single elements have an oxidation of zero.
- Alkali metals are always +1.
- Alkaline earth metals are always +2.
- Fluorine and most other halogens are -1.
- Oxygen is usually -2 except when with fluorine and if it is a peroxide.
- Nonmetals usually have negative values.
- Hydrogen is +1 when bonded with nonmetals.
- All oxidation numbers in a compound must equal zero.
- 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).
- Molarity = the number of moles of solute in a liter of solution.
- Process of dilution - add water to a more concentrated substance (the number of moles remains the same, only the volume changes).
Titrations are used to determine the concentration of unknown acids or bases using a known molarity of acid or base (standard solution = known solution).
- Use an indicator to determine the end point of the titration which is very close to the equivalence point.
- equivalence point of a titration is when chemically equivalent, or stoichiometric, amounts of reacts have reacted
- end point is the experimentally determined condition when an indicator or other signally device indicates that the end of the reaction has occurred
- Solubility and Solutions - Sept. 14-15
- Oxidation-Reduction Reactions - Sept. 19-20
- Acid-Base Titrations - Sept. 22
- True or False
- Study Guide, page 66, questions 4.1-4.34 - you will choose 20 of the 34 questions to answer.
- Identify substances as being ionic or covalent and describe the electrolytic behavior in water.
- Rank a given set of solutions in order of increasing conductivity in water.
- Complete and balance neutralization reactions, net ionic equations, and oxidation-reduction reactions
- Predict whether specific substances are soluble or insoluble in water
- Identify which substances in a reaction are being oxidized and which are being reduced
- Lab questions - discuss in class