| Videos: 17 results |
Vapor Pressure: Drinking Bird
A novelty store "Drinking Bird" repeatedly dips is beak into a beaker of water and then bobs back to an upright position. Visible movement of a liquid in the bird's body accompanies the bobbing; the movement is caused by changing vapor pressure of the liquid due to different temperatures at the bird's head and the bird's body.
Liquids |
Phases / Phase Transitions / Diagrams
|
Vapor Pressure of a Mixture: Raoult's Law
The measurement of pressure exerted by a vapor is demonstrated using barometers. Vapor pressure varies with the strength of the intermolecular forces in the liquid.
In this section we will look at vapor pressure of mixtures. We can calculate the vapor pressure of a mixture using Raoult's law.
Gases |
Liquids |
Noncovalent Interactions |
Phases / Phase Transitions / Diagrams |
Physical Properties
|
Vapor Pressure: Molecular Size
The measurement of pressure exerted by a vapor is demonstrated using barometers. Vapor pressure varies with the strength of the intermolecular forces in the liquid.
Gases |
Liquids |
Noncovalent Interactions |
Phases / Phase Transitions / Diagrams |
Physical Properties
|
Vapor Pressure
Pressure exerted by vapor of several organic substances is demonstrated using barometers. Molecular models of the substances are shown.
Gases |
Phases / Phase Transitions / Diagrams |
Physical Properties
|
Enthlapy-Thermodynamics
Reactions and demonstrations the explore thermodynamic concepts.
Precipitation / Solubility |
Solutions / Solvents |
Calorimetry / Thermochemistry |
Applications of Chemistry |
Acids / Bases |
Physical Properties |
Reactions |
Thermodynamics |
Gases |
Phases / Phase Transitions / Diagrams |
Water / Water Chemistry |
Liquids |
Solids |
pH |
Consumer Chemistry |
Kinetics |
Oxidation / Reduction
|
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
|
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
|
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
|
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
|
Atmospheric Pressure
Atmospheric pressure is used to collapse large and small metal containers.
Phases / Phase Transitions / Diagrams |
Gases |
Atmospheric Chemistry
|
Liquefaction of Carbon Dioxide
Dry ice is placed into an acrylic plastic cylinder. A valve is closed and pressure in the cylinder increases. When the pressure reaches 350 kPa (50 psi) it stops increasing and liquid CO2 appears.
Equilibrium |
Phases / Phase Transitions / Diagrams |
Physical Properties
|
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
|
Thermochromism: Mercury(II) Iodide
When red-orange Mercury(II) Iodide (HgI2) is heated, it undergoes a phase transition at 126oC to a pale yellow form. As the heated sample cools, it gradually returns to the original red-orange color.
Crystals / Crystallography |
Phases / Phase Transitions / Diagrams |
Physical Properties |
Solid State Chemistry |
Solids |
Descriptive Chemistry
|
Entropy
These processes are shown in reverse. The situations shown are so highly improbable that we would not expect to observe them in nature.
Thermodynamics
|
Endothermic Reaction
Solid barium hydroxide octahydrate (Ba(OH)2*8H2O) and ammonium thiocyanate (NH4SCN) are mixed in a beaker, which is then placed on a few drops of water on a small board. The reaction that occurs is highly endothermic.
Calorimetry / Thermochemistry |
Thermodynamics
|
Chemiluminescence
Luminol and light sticks are demonstrated.
Thermodynamics |
Applications of Chemistry |
Consumer Chemistry
|
TNT Detonation
TNT is stable in the presence of shock, but can be detonated by adding a chemical priming agent.
Oxidation / Reduction |
Thermodynamics |
Aromatic Compounds |
Reactions
|
