1210 – General Chemistry I

 

Chapter 1: Introduction: Matter, Energy, and Measurement

 

Chapter 2: Atoms, Molecules, and Ions

 

Chapter 3: Chemical Reactions and Reaction Stoichiometry

  • Avogadro’s Law
    • Three flasks containing equal amounts of acetic acid are fitted with balloons containing different amounts of NaHCO3; mix the reagents by lifting and shaking the balloons:  the balloons will inflate with CO2 to a volume proportional to the number of moles produced, in accordance with Avogadro’s law.
    • Avogadro’s Law.pdf
  • Burning Magnesium Ribbon
  • Combustion of Ethanol Vapors
    • Compare the combustion of ethanol in a small dish to the combustion of ethanol vapors.  When liquids are flammable, their vapors are explosive!
    • Combustion EtOH Vapor.pdf
  • Combustion vs. Fire
    • Contrast the burning of ethanol with the burning of magnesium ribbon.  One is combustion and the other is not.  Does fire always mean combustion?
    • Combustion vs. fire.pdf
  • Combustion of Magnesium in Dry Ice
    • Once ignited, magnesium burns without oxygen in a block of dry ice.  The single replacement reaction results in magnesium oxide and a ball of solid carbon.
    • Combustion of Magnesium in Dry Ice.pdf
  • Electrolysis of Water
    • Electrolyze water (Na2SO4 solution with indicator) in the Hoffman apparatus to decompose it into its component elements, hydrogen and oxygen.
    • Electrolysis of Water.pdf
  • Mole Samples
    • Show mole samples of various elements and compounds in bottles
  • Potassium and Water
    • Drop a piece of potassium into an aquarium containing water and phenolphthalein to produce H2 (g) and KOH (aq) – the heat of reaction ignites the H2 (g) and a lavender flame is observed (from the K+), while the indicator turns pink from the formation of KOH.
    • Potassium and Water.pdf

 

Chapter 4: Reactions in Aqueous Solution

 

Chapter 5: Thermochemistry

  • Combustion of Candy
    • Contrast the oxidation of sucrose in the body (by eating some candy) with the oxidation of sucrose by KClO3 (as shown by dropping some candy into molten KClO3, producing steam and a lavender flame. Body temperature is ~37°C, and the melting point of KClO3 is 368°C.
    • Combustion of Candy.pdf
  • Combustion of Methane Bubbles
  • Crystallization of Supersaturated Sodium Acetate
    • Add a tiny crystal of sodium acetate to a 2 L flask of a super-saturated solution to cause the solid to crystallize out, leaving almost no liquid – this demonstration is beautiful and dramatic, as well as being quite exothermic.
    • Crystallization of Supersaturated Sodium Acetate.pdf
  • Endothermic Reaction
    • Shake solid Ba(OH)2 • 8 H2O with solid NH4NO3 to produce an aqueous mixture of Ba(NO3)2 (s) and NH3 (aq). The reaction is endothermic enough to freeze the flask to a wet piece of cardboard. Alternatively, a digital thermometer can be used to record the temperature change.
    • Endothermic Reaction.pdf
  • Luminol
    • Pour solutions of luminol and H2O2 into a tall glass spiral to produce a beautiful chemiluminescent reaction.  The light-emitting species is the dicarboxylate ion, aminophthalate, the product of the oxidation of luminol with H2O2
    • Luminol Reaction.pdf
  • Sound
    • Tap a very small pile of red phosphorus and KClO3 with a hammer to show a reaction that produces light, sound, and heat, and recreates on a larger scale the reaction that occurs when you strike a match.
  • Thionine Reaction
    • Hold a solution of thionine and FeSO4 in front of a bright light to show the reduction of thionine from a violet form to a colorless form; this is an endothermic reaction that absorbs light energy.
    • Thionine.pdf

 

Chapter 6: Electronic Structure of Atoms

  • Atomic Spectra: Flame Tests
    • Introduce various metal salts (e.g. NaCl, SrCl2, CuCl2) into an open flame to produce brilliant colors associated with exciting metal cations
    • Flame Tests.pdf
  • Fireworks Balloons
    • Balloons filled with hydrogen gas and various salts and elements produce colored fireballs when ignited.
    • Fireworks Balloons.pdf
  • Gas Discharge Tubes of the Noble Gases
    • Show that different gases give different colors when subjected to an electric discharge (the noble gases and hydrogen)
    • Gas Discharge tubes.pdf
  • Pickle Electrocutor
    • Run an electric current through a dill pickle using a special apparatus to show students that the brine in the pickle conducts electricity, and the current heats and excites the sodium atoms present to a higher energy level.  The emission of photons as the sodium returns to the ground state accounts for the yellow color of the light.
    • Pickle Electrocutor.pdf
  • Orbital Models

 

Chapter 7: Periodic Properties of the Elements

 

Chapters 8 and 9: Basic Concepts of Chemical Bonding & Molecular Geometry and Bonding Theories

  • Paramagnetic O2
    • Demonstrate the paramagnetism of liquid oxygen by pouring first N2(ℓ), then O2(ℓ) between the poles of a powerful magnet on the overhead projector or document
      camera.
    • Paramagnetic O2.pdf
  • Polarity and Geometry
    • Show the dependence of dipole-dipole forces on geometry by contrasting the effect of a charged rod on streams of H2O and “CCl4” (actually hexane) flowing from burets.
    • Polarity and Geometry.pdf
  • VSEPR Shapes
    • Use ball-and-stick models to illustrate the VSEPR shapes and sub-shapes.
      • Linear
      • Trigonal Planar – trigonal planar and bent 120°
      • Tetrahedral – tetrahedral, trigonal pyramidal, and bent 109°
      • Trigonal Bipyramidal – trigonal bipyramidal, see-saw, T-shaped, and linear
      • Octahedral – octahedral, square pyramidal, square planar

 

Chapter 10: Gases

 

Chapter 11: Liquids and Intermolecular Forces