Hello Professors!!! Today is Friday, March 22nd
… And these are the hottest and trendiest demonstrations for the upcoming week!
The chemicals are absolutely flying off the shelves, so order while you can!
Here is the link (Password: hydrogen) to order as well as the full list of demos; as always, early orders are very appreciated!
General Chemistry I:
*Midterm Week Good Luck!
General Chemistry II:
Weekly topics
- Chemical Thermodynamics
- Electrochemistry
-
d-block elements (Transition metals)
Suggested Demonstrations
- Money to Burn – Soak a dollar bill in a water-alcohol mixture and then light it with a match; the high specific heat of water keeps the combustion temperature low enough to prevent burning the bill
- Multiple Oxidation States of Manganese – Starting with KMnO4(aq) in four beakers, carry out reactions to display manganese in the +7, +4, +3, and +2 oxidation states
- 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.
- 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.
General Chemistry for Engineers:
Weekly topics
- Chemical Kinetics
- Concentration dependence of rates
Suggested Demonstrations
- Iodine Clock Reaction – Perform the iodine clock reaction with three different initial concentrations of IO3-
- Alka Seltzer at Three Temperatures –Three students add Alka-seltzer tablets to flasks containing water at different temperatures and quickly seal the flasks with stoppers fitted with balloons, which will inflate at different rates
- H2/O2 balloon – Ignite a balloon filled with a stoichiometric mixture of hydrogen and oxygen to show the extremely exothermic reaction to produce water.
Elementary Chemistry:
Weekly topics
- Strong acids/bases
- Weak acids/bases
- Buffers
Suggested Demonstrations
- Acids and Bases – Add drops of 0.1 M NaOH to a magnetically stirred solution of water and universal indicator until it turns blue, then add drops of 0.1 M HCl until the solution turns orange.
- Strong and Weak Acids and Bases – Use two conductivity testers with light bulbs to contrast the conductivity of weak and strong electrolytes: acetic acid and HCl (aq), and/or NH3 (aq) and NaOH (aq)
- Acid-Base Titration – Add NaOH (aq) to a solution of HCl and phenolphthalein
- Acidic and Basic Oxides – Dissolve several oxides (CaO, ZnO, CO2, P4O10) in water containing universal indicator to show a range of basic and acidic oxides
- Yamada and Breath – Have a student wearing a white or light-colored shirt use a straw to blow into water containing Yamada universal indicator or to observe the color change accompanying the reaction
- Acidity and Basicity of Salts (Formerly Hydrolysis of Salts) – Dissolve various salts in water containing Yamada indicator to demonstrate their acidity or alkalinity in solution.
Foundations of General Chemistry:
Weekly topics
- Real gas laws
- Pressure
- Effusion/Diffusion
- Stoichiometry
Suggested Demonstrations
- Squashing Pop Cans with Atmospheric Pressure – use atmospheric pressure to squash pop cans
- Marshmallow Snowman – Demonstrate the effect a decrease in P has on V by placing a marshmallow snowman in a bell jar and then evacuate the jar
- Boiling Water at Room Temperature – Show water boiling at room temperature in a beaker in an evacuated bell jar, then put your hand in the water after boiling to convince students of its low temperature. (Upon request, we can give you a clean beaker and tap water if you want to drink the boiled water)
- Vanilla Balloons – Pass around a few balloons containing a potent osmophore (vanilla) and ask students to identify the odor; the odor is detectable because of the diffusion of vanillin molecules through pores in the balloon.
- Charles’ Law – Pour liquid nitrogen over a balloon to show that a decrease in T is accompanied by a decrease in V.
Thank you and have a great week!
–The Demo Lab
PS 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 🙂: Demo Ordering Link
Kind regards,
Lynda Reynolds