Author: meister.121

Suggested Demos for Week of April 15th – 19th

by at

Hello Professors! 

Today is Friday, April 12th, 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 

  • Solids and Modern Materials 

Suggested Demonstrations 

  • Crystalline and Amorphous Solids – contrast a piece of charcoal, a large quartz crystal, a piece of pumice, and a polished quartz crystal (SiO2). 
  • Unit Cells and Crystal Lattices –  
  1. i) Display ball-and-stick models of simple cubic, BCC, and FCC unit cells (Optional: Display space-filling models and/or extended lattice models).
  2. ii) Stack several space-filling FCC cubes or BCC cubes to show how unit cells form an extended lattice. 

iii) Pass around small unit cell models of simple cubic, BCC, and FCC. 

  1. iv) DIsplay unit cell models of NaCl or CsCl. 
  2. v) Illustrate hexagonal and cubic close-packed structures with layers of ping pong balls. 
  3. vi) Diffraction of Light – Use a laser pointer and a slide containing eight different arrays of dots to simulate x-ray diffraction experiments.
  • Metallic Solids – Show models of Cu, Mg, and Fe lattices. 
  • Ionic Solids –  
  1. i) Display models of NaCl, CsCl, ZnS, CaF2, and TiO2 
  2. ii) Display a model of CaCO3
  • Molecular Solids – 
  1. i) Show models of CO2 (s) and H2O (s) lattices. 
  2. ii) Show pairs of Darling models of benzene and toluene to illustrate the effect of structure and symmetry of molecules on their melting and boiling points.

 

General Chemistry II:  

Weekly topics  

  • Transition Metals 
  • Coordination Chemistry 
  • Crystal Field Theory 
  • Coordination Complex Isomerism 

Suggested Demonstrations  

  • Nickel and Cobalt Amine Complexes – show the dependence of color on both the metal ion and its oxidation state. Add concentrated ammonia to Ni2+ and Co2+ solutions to show different colors with the same ligand. Next, shake some of the resulting [Co(NH3)6]2+ complex with O2 to shift the oxidation state from Co2+ to Co3+, to show different colors with different oxidation states. 
  • Precipitates and Complexes of Nickel – Add different amounts of ethylenediamine to beakers of Ni2+ to contrast the colors of Ni(H2O)62+ and the Ni2+ chelate complexes with one, two, and three ethylenediamine molecules. 
  • 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 
  • Complex Ion Formation Ni and Cu – Show color change associated with formation of complex ions. In a tall graduated cylinder of Cu2+ or Ni2+ aqueous solutions, carefully add 6 M NH3 to create a layering effect of [M(H2O)62+ / M(OH)2 / [M(NH3)42+] 
    • CuSO4 gives a blue / white / dark blue layering 
    • Ni(NO3)2 gives a green / white / dark blue layering 
  • Paramagnetic and Diamagnetic Salts – Provide experimental evidence of electron spin by bringing a powerful magnet close to suspended test tubes of MnSO4, FeSO4, NiSO4, and ZnSO4 to show the different responses due to different numbers of unpaired electrons 

 

General Chemistry for Engineers:  

Weekly topics  

  • 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 Double Helix of DNA – Show a model of DNA 
  • 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 
  • 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. 
  • 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  

  • Crystalline and Modern Materials 
  • Fundamental crystalline types 
  • Atomic structures of materials 

Suggested Demonstrations  

  • Crystalline and Amorphous Solids – contrast a piece of charcoal, a large quartz crystal, a piece of pumice, and a polished quartz crystal (SiO2). 
  • Unit Cells and Crystal Lattices 
  1. Display ball-and-stick models of simple cubic, BCC, and FCC unit cells (Optional: Display space-filling models and/or extended lattice models). 
  2. Stack several space-filling FCC cubes or BCC cubes to show how unit cells form an extended lattice.
  3. Pass around small unit cell models of simple cubic, BCC, and FCC.  
  4. Display unit cell models of NaCl or CsCl. 
  5. Illustrate hexagonal and cubic close-packed structures with layers of ping pong balls. 
  6. Diffraction of Light – Use a laser pointer and a slide containing eight different arrays of dots to simulate x-ray diffraction experiments.
  • Metallic Solids – Show Models of Cu, Mg, and Fe lattices 
  • Ionic Solids 
  1. Display models of NaCl, CsCl, ZnS, CaF2, and TiO2
  2. Display a model of CaCO3
  • Molecular Solids  
  1. Show models of CO2 (s) and H2O (s) lattices. 
  2. Show pairs of Darling models of benzene and toluene to illustrate the effect of structure and symmetry of molecules on their melting and boiling points.
  • Covalent Network Solids – Show large models of different arrangements of pure carbon: graphite, diamond, and/or C60 (buckminsterfullerene). 

 

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

Suggested Demos for Week of April 8th – 12th

by at

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 

Suggested Demos for 3/29/24-4/5/24

by at

Hello Professors! 

Today is Friday, March 29th, 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 

  • Gas laws 
  • Pressure/Partial Pressure 
  • Effusion/Diffusion 

 

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. 

 

General Chemistry II:  

Weekly topics  

  • Electrochemistry 
  • Redox reactions 
  • Voltaic cells 
  • Electrolysis 

 

Suggested Demonstrations  

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

  • Equilibrium 
  • Solubility 
  • Le Chatelier’s Principle 
  • Acids & Bases

 

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 
  • Cobalt Complexes and Temperature v2.0 – Demonstrate effects of concentration and temperature changes on the Co(H2O)62+/CoCl42– equilibrium 
  • Effect of Temperature on NO2 ↔ N2O4 Equilibrium – Immerse sealed tubes of NO2/N2O4 in hot and cold water to show how temperature shifts the equilibrium position and to show the reversibility of the shift; red-brown NO2 predominates at high temperatures and colorless N2O4 at lower temperatures 
  • Acid-Base Titration – Add 1 M NaOH (aq) to a solution of 0.1 M HCl and phenolphthalein to show the endpoint. 

 

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 to show the endpoint. 
  • 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 

 

 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