Month: June 2024

CBC Demo Lab Weekly Digest

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Hello Professors!

To place your orders, please see the attached newsletter for links or the QR Code. Thanks

SU24 Week 6 Newsletter

More outreach fun: The CBC Demo Lab hosted show #1 of 2: Our friends from the Ohio Supercomputer Center-Summer Institute visited us for a 1-hr Long show full of Fun Demos! Above is Student Assistant, Sean, performing Combustion of Candy.

To order for Summer 2024, Please click here 🙂

or scan the QR Code:

Today is Friday, June 7th,

 And these are the trendies demonstrations for the upcoming week!

We are currently re-organizing our lab and the chemicals are just as confused of their location as we are … so while they are still (somewhere) on our shelves, order while you can!

Use the link (Password: hydrogen) to order as well as the full list of demos; as always, early orders are very appreciated!

General Chemistry I

Weekly topics

  • Thermochemistry
  • Basic Concepts of Chemical Bonding
  • Molecular Geometry and Bonding Theories

Thermochemistry

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.

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.

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.

Basic Concepts of Chemical Bonding

Contrast models of NH2—NH2, NH=NH, and N≡N to show the decreasing N–N bond length as the bond order increases

Show orbital overlap models of ethane, ethene, and ethyne (acetylene)

Molecular Geometry and Bonding Theories

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.

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.

Use ball-and-stick models to illustrate the VSEPR shapes and sub-shapes. Normal order is for the parent shapes. You must specify if you want 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.
  • Octahedral – octahedral, square pyramidal, square planar

General Chemistry II

Weekly topics

  • Electrochemistry

Electrochemistry

 Multiple Oxidation States of Vanadium – Shake a solution of ammonium meta-vanadate with a Zn-Hg amalgam to reduce the vanadium from +5 to +4 to +3 to +2 with different colors at each stage.

Metal Redox Reactions – Compare redox reactions between metals and metal ions to see which is spontaneous.

Copper/Zinc Voltaic Cell – Demonstrate a copper/zinc voltaic cell turning a motor to show that a spontaneous reaction can be harnessed to do work.

  • Pass around a disassembled 9 V battery to show that it is comprised of six 1.5 V cells.

Electrolysis of Water – Electrolyze water (dilute Na2SO4 solution with indicator) in the Hoffman apparatus to decompose it into its component elements, hydrogen and oxygen. If desired, you can test the H2 (g) and/or O2 (g) produced with a flame and a glowing splint, respectively.

Have a great week!

P.S. If you are ahead/behind of schedule, let us know so we can adjust the demos accordingly. Currently we are simply using the syllabi to guess where your respective classes are at.  And here is the link again