Section 16: Gases
Section 16A: Pressure
Units, Common Gases, Atmospheric Pressure, Barometer, Manometer
Pressure is a commonly used term, but what does it exactly mean? If something is under a great deal of pressure, how is that statement interpreted? Once the idea of pressure is understood, a unified unit of measure must be used. In the case of pressure there are several different units which are based on different things. The idea of high and low pressure weather systems is something that has been seen on TV. High and low pressures relative to what? There needs to be an understanding of what air pressure is on a normal basis. The instrument used to measure this is called a barometer. This device was developed by an individual named Evangelista Torricelli.
Pressure is a commonly used term, but what does it exactly mean? If something is under a great deal of pressure, how is that statement interpreted? Once the idea of pressure is understood, a unified unit of measure must be used. In the case of pressure there are several different units which are based on different things. The idea of high and low pressure weather systems is something that has been seen on TV. High and low pressures relative to what? There needs to be an understanding of what air pressure is on a normal basis. The instrument used to measure this is called a barometer. This device was developed by an individual named Evangelista Torricelli.
Section 16B: Gas Laws
Robert Boyle, Jacques Charles, Joseph Gay-Lussac, Amedeo Avogadro, Combined Gas Law, Ideal Gas Law
The beauty of the gases is that they are easily described with equations. What is the benefit of being able to describe a state of matter with equations? How is this helpful for scientists? There are six gas laws listed above, each is based on a different aspect of a gas. Also, no matter what gas is being described, each equation still holds true. Meaning that no matter what the formula of the gas that is being studied, the physical properties of the gas are no different than other gases.
The beauty of the gases is that they are easily described with equations. What is the benefit of being able to describe a state of matter with equations? How is this helpful for scientists? There are six gas laws listed above, each is based on a different aspect of a gas. Also, no matter what gas is being described, each equation still holds true. Meaning that no matter what the formula of the gas that is being studied, the physical properties of the gas are no different than other gases.
BrightStorm
|
Practice
|
Resources
|
Section 16C: Partial Pressure
Mole Fraction, Calculating Partial Pressure
John Dalton did more than just come up with a theory that dethroned Aristotle as the experiment on the composition of matter. He developed an equation that described how mixtures of gases behaved. He understood that when two gases are mixed, the sum of the pressure of each gas will equal the total pressure of the system.
John Dalton did more than just come up with a theory that dethroned Aristotle as the experiment on the composition of matter. He developed an equation that described how mixtures of gases behaved. He understood that when two gases are mixed, the sum of the pressure of each gas will equal the total pressure of the system.
Section 16D: Kinetic Molecular Theory
Relationship to States of Matter, Assumptions, Root-Mean-Square Speed, Diffusion, Effusion, Real Gases, van der Waals Equation
To start understanding this theory, the name should be broken down into components. What does that word "kinetic" mean? "Molecular" relates to what objects? What does the word "theory" mean? Although this theory applies mainly to the gaseous phase, it can help explain the behavior of the other two phases. There are several equations and ideas that explain how gas particles move and interact with one another. The ideal gas law does a very good job of approximating behavior of gases, but does not account for the volume of a gas particle nor the attractive forces that exist between gas particles. Johannes van der Waals developed an equation that accounted for the interactions between molecules as well as the volume of the gas particles in a container.
To start understanding this theory, the name should be broken down into components. What does that word "kinetic" mean? "Molecular" relates to what objects? What does the word "theory" mean? Although this theory applies mainly to the gaseous phase, it can help explain the behavior of the other two phases. There are several equations and ideas that explain how gas particles move and interact with one another. The ideal gas law does a very good job of approximating behavior of gases, but does not account for the volume of a gas particle nor the attractive forces that exist between gas particles. Johannes van der Waals developed an equation that accounted for the interactions between molecules as well as the volume of the gas particles in a container.