1 / 14

Gases

Gases. KMS 8 th Grade Science Ms. Bormann. The Nature of Gases. The first gas to be studied was air & it was a long time before it was discovered that air was actually a mixture of particles rather than a single gas.

bertha
Download Presentation

Gases

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Gases KMS 8th Grade Science Ms. Bormann

  2. The Nature of Gases • The first gas to be studied was air & it was a long time before it was discovered that air was actually a mixture of particles rather than a single gas. • Although air is a mixture of several different gases, it behaves much the same as any single gas. • Regardless of their chemical identity, gases tend to exhibit similar physical behaviors

  3. Characteristics of Gases

  4. The Kinetic Molecular Theory • Kinetic = • Molecular = • The theory states Motion Molecules the tiny particles in all forms of matter are in constant motion.

  5. Boyle’s Law • Robert Boyle was among the first to note the relationship between of a gas. • During his experiments and were NOT allowed to change. • Boyle’s Law states • For example: If the volume is halved, the pressure would be pressure and volume temperature the amount of gas The pressure exerted by a gas held at constant temperature varies inversely with the volume of the gas. doubled

  6. Pressure Pressure – amount of force exerted per unit of area. • Pa = Pascal. SI unit for pressure. One Pascal of pressure is 1 Newton per square meter – therefore a Pascal is a very small unit. • kPa = kilopascal. A kilopascal is 1,000 Pa. • Example: At sea level atmospheric pressure is 101.3 kPa. This means that at Earth’s surface, the atmosphere exerts a force of 101,300 Newton’s on every square meter (this is about the weight of a large truck) • Atm = standard atmosphere. 101.3 kPa or 101,300 Pa

  7. Boyle’s Mathematical Law P1V1 = P2V2 • A gas has a volume of 3.0 L at 2 atm. What is its volume at 4 atm?

  8. Boyle’s Law • 1. Determine which variables you have • 2. Determine which law is being represented • 3. Rearrange the equation for the unknown variable. • 4. Plug in the variables and solve. • P1= 2 atm • V1= 3.0 L • P2= 4 atm • V2= ? P and V = Boyle’s Law

  9. Charles’s Law • Jacques Charles was among the first to note the relationship between of a gas. • During his experiments and are NOT allowed to change. • Charles’s Law states • For example: If the temperature is increased, the pressure will temperature and volume pressure the amount of gas At constant pressure, the volume of a fixed number of particles of gas is directly proportional to the absolute (Kelvin) temperature increase

  10. Temperature Charles' Law must be used with the Kelvin temperature scale. This scale is an absolute temperature scale. At 0 K, there is no kinetic energy (Absolute Zero). According to Charles' Law, there would also be no volume at that temperature. This condition cannot be fulfilled because all known gases will liquefy or solidify before reaching 0 K.

  11. Charles’s Mathematical Law • Eg: A gas has a volume of 3.0 L at 127°C. What is its volume at 227 °C?

  12. Charles’s Law • 1. Determine which variables you have • 2. Determine which law is being represented. • 3. Plug in variables • 4. Cross multiply and solve • T1= 127°C + 273 = 400K • V1= 3.0 L • T2= 227°C + 273 = 5ooK • V2= ?

More Related