Module 3 Intro

Module 3—Behaviour of Gases

Big Picture

 

The term gas was first used in 1663 to describe a specific form of matter. Johann von Helmont, a Belgian physician, derived the word from the Greek word chaos, which referred to the “great abyss” from which Earth was supposedly formed. Some have suggested that von Helmont chose the word chaos because his equipment kept exploding when he tried to make gases.

 

Gases have many easily observable properties that have made them very interesting to study. Gases are fluids, meaning they fill whatever space is available, and they can be compressed by applied pressure. They are affected by temperature, can flow readily from place to place, and have mass.

 

Watch the following video. You may be required to login with a username and password. Contact your teacher for this information. As you watch the video, select the inquiry track. Write down your answers to the questions that are asked on the video. To check your answers, you can review this video with the explanatory track selected.

 

http://www.learnalberta.ca/content/secr/Gases/expanding_marshmallow/chem.html

 

Read through the Case Study “Compressed Gases” on pages 159 and 160 of your textbook to gain an appreciation of some of the ways compressed gases are used.

 

In this module you will investigate the empirical relationships that exist among pressure, volume, temperature, and amount of gas in a system. You will also use your understanding of bonding concepts from Unit A to explain at a theoretical level the behaviour you observe.

 

The following questions will be investigated in this module:

• What is pressure?
  
  
• How is pressure measured?
  
  
• How are pressure and volume of a gas related?
  
  
• How are pressure-volume relationships applied in technologies to support breathing?
  
  
• What is the Kelvin temperature scale, and why is it used?
  
  
• What are the relationships among amount, pressure, volume, and temperature for a fixed amount of gas?
  
  
• Is it possible to predict the quantity of a gaseous substance involved in a chemical reaction?
  
  
• What is molar volume?
  
  
• What is the difference between a real gas and an ideal gas?
  
  
• What relationship exists between pressure, volume, temperature, and moles of gas?

In this module you will apply your understanding of relationships among pressure, volume, temperature, and amount of gas to explain the function of common technologies.

 

The assessment for this module is combined with the unit assessment. For more information about the combined module and unit assessment, go to the Unit Assessment section.