| Videos: 54 results |
Temperature
Use of a thermometer is demonstrated with examples including the use of melting point apparatuses and calorimeters.
Laboratory Equipment / Apparatus
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Controlling the Temperature
The need and methods to control the heating rate near the melting point of the solid are demonstrated.
Laboratory Equipment / Apparatus
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Reactions: Reflux at Constant Temperature
The technique of refluxing a reaction mixture is demonstrated.
Laboratory Equipment / Apparatus
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Sulfuric Acid into Water and Ice
When sulfuric acid is mixed with water the temperature rises. When sulfuric acid is added to ice, the temperature rises at first, but as the ice melts, the temperature falls.
Calorimetry / Thermochemistry
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Rates of Reactions
The effects of a variety of variables, including concentration, temperature and catalysts, on reaction rate are shown.
Kinetics
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Phase Changes
By using a coolant at a temperature below the boiling point of the gases chlorine, bromine and iodine, the gases are condensed into liquid form.
Phases / Phase Transitions / Diagrams
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Critical Point of Benzene
A sealed tube containing benzene liquid and vapor is heated. As the critical temperature is approached, the meniscus flattens. At the critical temperature the meniscus disappears, and separate liquid and vapor phases can no longer be detected.
Phases / Phase Transitions / Diagrams
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Measuring
Measurement of electrical properties, mass, pH, pressure, volume, and temperature are demonstrated along with examples of recording data, spectroscopy, and titration.
Laboratory Equipment / Apparatus |
Quantitative Analysis
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Steam and Superheated Steam
When a gas burner heats the steam coil strongly, the steam becomes superheated and is at a high enough temperature to ignite a match and react quickly with steel wool
Gases |
Phases / Phase Transitions / Diagrams
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Light as a Particle: Photoelectric Effect
The discovery of the temperature dependence of the spectrum of an incandescent light source and the discovery of the photoelectric effect led to the characterization of the particle-like properties of light. Here we demonstrate these two phenomena.
Quantum Chemistry
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Steam and Superheated Steam
Water is boiled and the steam is collected and run through a coil of copper tubing. When a gas burner heats the steam coil strongly, the steam becomes superheated and is at a high enough temperature to ignite a match and react quickly with steel wool.
Applications of Chemistry |
Gases |
Phases / Phase Transitions / Diagrams |
Water / Water Chemistry
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Boiling by Cooling
A flask contains water and water vapor at 100C. Each time ice water is poured over the outside of the flask, the water inside the flask boils. Although the temperature of the water in the flask has decreased, in each instance boiling is observed.
Gases |
Liquids |
Phases / Phase Transitions / Diagrams
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Superconductivity
A pellet of 1-2-3 yttrium barium copper oxide (YBa2Cu3O7-x) is cooled with liquid nitrogen. A magnet placed above the pellet is levitated. At a higher temperature the magnet rests on the pellet, but cooling once again causes the magnet to rise. The levitated magnet is spun with plastic tweezers
Phases / Phase Transitions / Diagrams |
Superconductivity
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Iodine Clock Reaction
A solution of hydrogen peroxide and sulfuric acid is added to a solution containing iodide ion, thiosulfate ion, and starch. After some time the dark blue color of a triiodide-starch complex is observed. The influences of initial reactant concentrations on the reaction time are examined, as are the influence of volume and temperature.
Kinetics |
Oxidation / Reduction
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Exploding Soap Bubbles: Hydrogen + Oxygen
A series of three videos shows that as the ratio of oxygen to hydrogen in soap bubbles increases, the explosions that occur when the bubbles are ignited get louder. (The fact that with an excess of oxygen the explosions would become softer again is not shown.) Each video is repeated with no voice-over so that only the sounds of the explosions are heard. Five still images are provided to show the stoichiometry on the molecular scale. The videos are intended to be shown in order beginning with Hydrogen Alone and ending with hydrogen plus more oxygen.
Reactions |
Oxidation / Reduction
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Reaction, Microscale: Tin with Gold(III) Chloride
A piece of metallic tin is carefully combined with a solution of gold(III) chloride under a microscope.
Oxidation / Reduction |
Reactions
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Oxidation-Reduction (Redox) Reactions
Demonstrations exploring oxidation/reduction chemistry.
Aqueous Solution Chemistry |
Electrochemistry |
Oxidation / Reduction |
Water / Water Chemistry |
Acids / Bases |
pH |
Conductivity |
Reactions |
Applications of Chemistry |
Descriptive Chemistry |
Electrolytic / Galvanic Cells / Potentials |
Laboratory Equipment / Apparatus
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Reactions Under a Microscope
Microscale redox and precipitation reactions.
Oxidation / Reduction |
Reactions |
Precipitation / Solubility
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Discovery Videos Lyubov Hoffman Laroche, Gary Wulfsberg, Barbara Young
The use of digital video for instruction has many advantages. In many situations the only way to present some chemical phenomena is through the use of video. The two video lessons presented here are examples intended to supplement our article in the August 2003 issue of JCE.
Descriptive Chemistry |
Periodicity / Periodic Table
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Denaturation of Protein by Strong Acid John W. Moore, Jerrold J. Jacobsen, Gary Trammell, Kristin Johnson
"Strong acid denatures egg white proteins.This video contains voiceover:""The tertiary structure of egg white proteins is held together by hydrogen bonding and hydrophobic interactions. Adding strong acid to the protein disrupts the intermolecular forces, and the tertiary structure is lost. The loss in protein structure is called denaturation. The proteins precipitate, forming a white solid."""
Acids / Bases |
Proteins / Peptides
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Which Is Hot John W. Moore, Jerrold J. Jacobsen, Lois M. Browne, John F. Zimmerman
"Two identical test tubes are shown; one is hot, and one is not. This video contains voiceover: Hot glass looks just like cold glass but it can cause severe burns. Be Careful!"
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Centrifuging a Sample John W. Moore, Jerrold J. Jacobsen, Lois M. Browne, John F. Zimmerman
The demonstration on this page shows a technique that should not be used by undergraduate chemistry laboratory. This video shows what happens to sample in a centrifuge while the centrifuge is on, and the result of stopping the centrifuge improperly. A narrative is included in this video: The centrifuging process allows the solvent to completely settle out. The jarring caused by hand braking destroys the distinct separation between supernatant and solid.
Separation Science |
Laboratory Equipment / Apparatus
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Chemistry Comes Alive! John W. Moore, Jerrold J. Jacobsen
Chemistry truly does come to life through this collection of pictures, animations, and movies depicting chemical reactions and techniques. The Chemistry Comes Alive! collection includes hundreds of high quality QuickTime movies and thousands of still pictures.
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ChemPages Laboratory Resources John W. Moore, Jerrold J. Jacobsen, Joe L. March
The Laboratory Resources are a set of web pages that include text, images, video, and self check questions. The topics included are those that are commonly encountered in the first-year chemistry laboratory. They have been put together for use as both a pre-laboratory preparation tool and an in-laboratory reference source.
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Electrochemical Cells
Techniques involved in measuring the voltage of an electrochemical cell and some common errors in constructing electrochemical cells are demonstrated.
Electrolytic / Galvanic Cells / Potentials |
Laboratory Equipment / Apparatus
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Reaction, Microscale: Mercury With Silver Nitrate
A droplet of mercury is carefully combined with a solution of silver nitrate under a microscope.
Oxidation / Reduction |
Reactions
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Reactions, Microscale: Precipitation
Here we show two precipitation reactions under a microscope. They are potassium dichromate crystal with silver nitrate and potassium iodide with lead nitrate.
Precipitation / Solubility |
Reactions
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Reactions, Microscale: Oxidation-Reduction
Three oxidation-reduction reactions are shown under a microscope. They are silver with mercury chloride, aluminum with gold chloride, and tin with gold chloride.
Oxidation / Reduction |
Reactions
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Reaction, Microscale: Potassium Dichromate with Silver Nitrate
A crystal of potassium dichromate is carefully combined with a solution of silver nitrate under a microscope. The reaction takes some time, so it is shown in a series of seven sequential videos. To see the entire reaction you need to play all seven.
Precipitation / Solubility |
Reactions
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Reaction: Sodium with Acids
Reaction of sodium with acid.
Acids / Bases |
Descriptive Chemistry |
Oxidation / Reduction |
Reactions
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Reactions: Nonmetals with Water
Nonmetallic elements are shown reacting with water.
Descriptive Chemistry |
Oxidation / Reduction |
Reactions |
Water / Water Chemistry
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Reactions: Nonmetals with Air
Various nonmetallic elements reacting with air are shown.
Descriptive Chemistry |
Oxidation / Reduction |
Reactions
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Reactions: Nonmetals with Base
Nonmetallic elements are shown reacting with bases.
Acids / Bases |
Descriptive Chemistry |
Oxidation / Reduction |
Reactions
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Reactions: Nonmetals with Acids
Nonmetallic elements are shown reacting with acids.
Acids / Bases |
Descriptive Chemistry |
Oxidation / Reduction |
Reactions
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Oxidation-Reduction Reactions
Electrolysis reactions and the action of nitric acid on iron and copper illustrate the concepts of oxidation and reduction. Also three oxidation-reduction reactions are shown under a microscope.
Oxidation / Reduction |
Descriptive Chemistry |
Reactions
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Ammonia Fountains
An ammonia fountain is demonstrated.
Acids / Bases |
Aqueous Solution Chemistry |
pH |
Precipitation / Solubility
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Acid Base Reactions of Sulfur Dioxide
Acid base reactions involving sulfur dioxide are shown.
Acids / Bases |
Gases |
Reactions |
Oxidation / Reduction |
Precipitation / Solubility |
Descriptive Chemistry |
Applications of Chemistry
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Reaction: Potassium with Water
Demonstrations of potassium reacting in water.
Descriptive Chemistry |
Water / Water Chemistry
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Oscillating Reaction: Briggs-Rauscher
When a solution of malonic acid, starch, and manganese(II) ion is added to a solution of hydrogen peroxide, iodate ion, and sulfuric acid, gas bubbles form and the color of the resulting mixture oscillates periodically from colorless to amber to blue.
Kinetics |
Oxidation / Reduction |
Electrolytic / Galvanic Cells / Potentials
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Reactions: Alkali Metals with Acids
Alkali metals are shown reacting with acids.
Acids / Bases |
Descriptive Chemistry |
Oxidation / Reduction |
Reactions
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Reactions: Alkali Metals with Base
Alkali Metals are shown reacting with base.
Acids / Bases |
Descriptive Chemistry |
Oxidation / Reduction |
Reactions
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Reactions: Alkaline Earth Metals with Water
Alkali earth metals are shown reacting in water.
Descriptive Chemistry |
Oxidation / Reduction |
Reactions |
Water / Water Chemistry
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Combustion Reactions
A number of dramatic combustion reactions are demonstrated.
Descriptive Chemistry |
Reactions |
Applications of Chemistry
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Reactions of Sulfuric Acid
Reactions of materials reacting with sulfuric acid are shown.
Acids / Bases |
Oxidation / Reduction |
Reactions |
Descriptive Chemistry |
Aqueous Solution Chemistry |
Precipitation / Solubility
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Reactions: Alkali Metals with Other Elements
Alkali Metals are shown reacting with various elements.
Oxidation / Reduction |
Reactions |
Descriptive Chemistry
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Reactions: Alkaline Earth Metals with Acids
Alkali earth metals are shown reacting with acids.
Acids / Bases |
Descriptive Chemistry |
Oxidation / Reduction |
Reactions
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Reactions: Alkaline Earth Metals with Air
Alkali earth metals are shown reacting in air.
Descriptive Chemistry |
Oxidation / Reduction |
Reactions
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Electrolysis
Various examples of electrolysis are presented.
Aqueous Solution Chemistry |
Electrochemistry |
Oxidation / Reduction |
Water / Water Chemistry |
Acids / Bases |
pH |
Conductivity
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Reactions: Alkali Metals with Water
Alkali Metals are shown reacting in water.
Descriptive Chemistry |
Oxidation / Reduction |
Reactions |
Water / Water Chemistry |
Acids / Bases
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Reactions: Alkali Metals with Air
Alkali Metals are shown reacting in air.
Descriptive Chemistry |
Oxidation / Reduction
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Reactions: Magnesium and Magnesium Compounds
Videos in this group show chemical reactions of magnesium and of magnesium ions in solution.
Applications of Chemistry |
Oxidation / Reduction |
Reactions
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Standing Waves on a Wave Demonstrator (with frequency)
The relationship between frequency and wavelength for standing waves on a 0.90 m short-rod wave demonstrator is explored. The frequency is displayed at the bottom of the screen.
Quantum Chemistry
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Hydrogen Balloon Explosions
Balloons containing various substances and hydrogen are exploded, revealing characteristic flame colors. In all cases except one, the substance had been mixed with methanol and water.
Descriptive Chemistry |
Spectroscopy
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Cadmium Nitrate with Sodium Sulfide
Here, sodium sulfide (Na2S) is added to cadmium nitrate (Cd(NO3)2). The result is a deep yellow-orange precipitate.
Aqueous Solution Chemistry |
Precipitation / Solubility |
Reactions
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