Hello Professors! 

Today is Friday, April 5th, 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:  

Weekly topics 

• Liquids and Intermolecular Forces 
• Phase Changes/Phase Diagrams 
• Vapor Pressure 

Suggested Demonstrations 

• 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) 
• Dry Ice Sublimation – Make the sublimation of dry ice “visible” by dropping a piece of dry ice in a beaker of water. (Optional: place a piece of dry ice in a glove, tie it off, and allow the dry ice to sublime, inflating the glove.) 

• Changes of state – Pour liquid nitrogen into a beaker to demonstrate a variety of phase changes: the boiling of N2(ℓ), the deposition of H2O(g) as H2O(s) on the outside of the beaker, and the melting of H2O(s) to H2O(ℓ) as the beaker eventually warms up again 
• Triple Point of CO2 – Demonstrate the existence of three phases of CO2 at the triple point by adding crushed dry ice to a clear acrylic tube fitted with a pressure gauge and a release valve 

 

General Chemistry II:  

Weekly topics  

• Nuclear Chemistry 
• Fusion and Fission 
• Radioactive Decay 

Suggested Demonstrations  

• Detection of Radioactivity – Use a Geiger counter to demonstrate the radioactivity (or lack thereof) of several substances, including NaI, NaC and uranium salts. A sheet of lead is provided to display the ability of lead to block radiation. 
• Nuclear Fission – Display one liter (1 kg) of water and a cube of aluminum the size of 1 kg of uranium (3.75 cm on a side), both to contrast the densities of water and uranium and to accompany a calculation of the amount of energy released from fission of 1 kg of uranium 

 

General Chemistry for Engineers:  

Weekly topics  

• Equilibrium 
• Solubility 
• Redox reactions 
• Galvanic Cells/Electrolysis 

Suggested Demonstrations  

• Le Chatelier’s Principle: Iron(III) Thiocyanate Equilibria – Apply stress to the Fe3+ + SCN- → FeSCN2+ system in five different ways to show the equilibrium shifts accompanying changes in the concentration of reactants 
• Acid-Base Titration – Add 1 M NaOH (aq) to a solution of 0.1 M HCl and phenolphthalein to show the endpoint. 
• 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. 
• Balancing a Redox Equation: MnO4- /NO2 – – Reduce pink MnO4- with NO2- in aqueous solution to produce colorless Mn2+ 
• Burning Magnesium Ribbon – Burn a piece of magnesium ribbon in air to produce MgO 

 

Elementary Chemistry:  

Weekly topics  

• Proteins 
• Protein Structure & Function 
• Denaturation of Proteins 
• Enzymes & Cofactors 

Suggested Demonstrations  

• The Biological Role of Proteins – To show the function of the structural protein collagen, contrast a regular turkey drumstick with a rehydrated “rubberized” turkey drumstick from which Ca3(PO4)2 and other minerals have been dissolved. 
• Amino Acids: The Building Blocks of Proteins – Show models of simple amino acids: glycine and alanine 
• Structure of Proteins – Display a telephone cord and point out various features of its configuration to help students understand by analogy the terms primary, secondary, and tertiary structure of proteins 
• Catalysis of a Reaction – Remind students of the function of a catalysis by demonstrating the catalysis of the H2O2 decomposition of NaK-tartrate with Co2+. Adding Co2+ turns the solution pink, but the solution quickly turns dark green as it begins to react vigorously. At the end of the reaction, the pink color is restored showing regeneration of the catalyst; 
• Catalytic Decomposition of H2O2 – Compare and contrast several different catalysts, including chicken liver, used for the decomposition of hydrogen peroxide 

 

Foundations of General Chemistry:  

Weekly topics  

• Solids/Liquids/Gases 
• Intermolecular Forces 
• Vaporization/Sublimation 
• Vapor Pressure 
• Phase Diagrams 

Suggested Demonstrations  

• Dry Ice Sublimation – Make the sublimation of dry ice “visible” by dropping a piece of dry ice in a beaker of water. (Optional: place a piece of dry ice in a glove, tie it off, and allow the dry ice to sublime, inflating the glove.) 
• Changes of state – Pour liquid nitrogen into a beaker to demonstrate a variety of phase changes: the boiling of N2(ℓ), the deposition of H2O(g) as H2O(s) on the outside of the beaker, and the melting of H2O(s) to H2O(ℓ) as the beaker eventually warms up again 
• Combustion of Ethanol Vapors – Allow a small amount of ethanol to vaporize in a large carboy, pour out the excess liquid, and hold a lighted splint to the mouth of the container – the impressive reaction also demonstrates the flammability of organic vapors. 
• 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) 
• Triple Point of CO2 – Demonstrate the existence of three phases of CO2 at the triple point by adding crushed dry ice to a clear acrylic tube fitted with a pressure gauge and a release valve 

 

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