Chapter 3 Lecture Outline

Introduction to Chemical Equations

Balancing Chemical Equations

1. Symbolism of chemical formula
2. Types of Reactions
1. Combination Reactions (two elements or compounds combine)
A + B - > AB
2. Decomposition Reactions (something breaks down)
AB -> A + B
3. Displacement Reactions (Switch reactants)
AB + CD -> AD + BC
3. Demonstrations:
1. Demonstrate Electrolysis of Water and balance equations
1. H₂O(l) -> H₂(g) + O₂(g) (Decomposition)
2. H₂(g) + O₂(g) -> H₂O(l) (Combination)

2. Demonstrate mixing baking soda with vinigar makes a fizz (bring matches):
1. Baking Soda + Viniger -> ?
2. Sodium Bicarbonate + Acetic Acid (Hydrogen Acetate)
3. NaHCO₃(s) + HC₂H₃O₂ (aq) -> Na⁺(aq) + H₂O(aq) + CO₂(g) + C₂H₃O₂^- (aq)
3. Demonstrate precipitation of silver chloride
   1. NaCl(s) -> Na¹⁺(aq) + Cl^1-(aq)
   2. AgNO₃ (s) -> Ag¹⁺ (aq) + NO₃^1-(aq)
   3. Ag¹⁺ (aq) + Cl^1-(aq) -> AgCl (s)
   4. NaCl (aq) + AgNO₃ (aq) -> AgCl (s) + NaNO₃ (aq)
4. More Examples
   1. Fe(s) + Cl₂(g) -> FeCl₃(s) (Do this one on board)
   2. Fe(s) + Cl₂ (g) -> FeCl₂ (s)
   3. NaOH(aq) + H₂SO₄ -> Na₂SO₄ (aq) + H₂O (l)
   4. NaOH (aq) + HCl -> H₂O + Na⁺ (aq) + Cl^- (aq)
   5. C₈H₁₈ + O₂ -> CO₂ + H₂O
   6. KO₂ (s) + H₂O(g) + CO₂ (g) -> KHCO₃ (s) + O₂ (g)
   7. CH₄ (g) + O₂ (g) -> CO₂ (g) + H₂O (g)
   8. C₄H₁₀ combustion

Chemical Reactions in Aqueous Solution

Ions and Molecules in Aqueous Solution

1. Ions in Solution
   1. Structure of Ionic Compounds (overhead fig 3.13)
   2. Solvation of Ionic Compounds (overhead fig 3.15)
   3. KMnO₄ ( , Internet© Saunders, 1997)
   4. Strong and Weak Acids & Bases, CD-ROM 4-7 & 4-8 (overhead table 4.1)

Precipitation Reactions

1. potassium chromate and lead nitrate produces lead chromate and potassium nitrate( ,Internet© Saunders, 1997) )
   K₂CrO₄ (aq) + Pb(NO₃)₂ (aq) - > PbCrO₄ (s) + 2 KNO₃ (aq)

2. lead nitrate and potassium iodide produces lead iodide and potassium nitrate( Internet© Saunders, 1997)
   Pb(NO₃)₂ (aq) + 2 KI (aq) -> PbI₂ (s) + 2 KNO₃ (aq)

3. silver nitrate and sodium chloride produces silver chlroide and sodium nitrate( Internet© Saunders, 1997)
   AgNO₃ (aq) + NaCl aq) - > AgCl (s) + NaNO₃ (aq)

4. iron (III) Ions + Sodium hydroxide produces iron (iii) hydroxide and sodium ions( Internet)
   Fe³⁺ (aq) + 3 NaOH (aq) - > Fe(OH)₃ (s) + 3 Na¹⁺(aq)

5. Solubility Rules (Overhead)

Acids and Bases

1. Definitions of acids and bases
1. Arrhenius definition (in water only)
1. Acids, produce H⁺ in water solution: HCl (aq) -> H⁺(aq) + Cl^-
2. Bases, produce OH^- in water solution: NaOH(aq) -> Na⁺ + OH^-
2. Bronsted-Lowry Acids and bases (more general definition)
1. Acids are proton donors in a chemical reaction
1. HCl (g) + H₂O -> H₃O⁺ + Cl^-
2. Acid + Base -> Base + Acid
2. Bases are proton acceptors in a chemical reaction
1. NaOH + H₂O -> Na⁺ + H₃O⁺
2. Base + Acid -> Acid + Base
2. Common Acids (know names of all strong acids)
1. Monoprotic - Single H⁺
2. Polyprotic - more than 1 H⁺, ie: diprotic, triprotic
1. H₂SO₄ + H₂O -> H₃O¹⁺ + HSO₄^1-
2. HSO₄^1- + H₂O -> H₃O¹⁺ + SO₄^2-
3. Strong acids (dissociate completely)
4. Weak acids (partially dissociate, introduce equlibrium)
3. Common Bases
1. Strong Bases (alkali metal hydroxides)
2. Weak bases (ammonia)
4. Aqueous Acid-Base Reactions
1. Total Equation: HCl(aq) + NaOH(aq) -> H₂O(l) + NaCl(aq)

2. Ionic Equations
1. Dissociation
1. HCl (g) -> H⁺(aq) + Cl^-(aq) OR HCl(g) + H₂O(l) -> H₃O⁺(aq) + Cl^-(aq)
   
2. NaOH -> Na⁺(aq) + OH^-(aq)
2. Neutralization (spectator ions): H₃O⁺ + Cl^- + Na⁺ + OH^- -> 2 H₂O + Na⁺ + Cl^-

3. Net Ionic Equation: H₃O⁺ + OH^- -> 2 H₂O
5. Example Reactions
   1. Magnesium Hydroxide + Nitric Acid
   1. Total equation
   2. Ionic Equation
   3. Net ionic equation
   2. Sulfuric acid and lithium hydroxide
   1. Total equation
   2. Ionic Equation
   3. Net ionic equation
   3. Acetic acid and iron (III) hydroxide
   1. Total equation
   2. Ionic Equation
   3. Net ionic equation
   4. Ammonia (NH₃) and water( Internet)
   5. hydrochloric acid and ammonia produces ammoinum and chloride
   6. hydrochloric acid and sodium hydroxide produces sodium chloride and water; no indicator

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