OWL Tutorial 2A

 

OWL T ut uto or i al 2A 2A-P -Prr ep ( C h.5.5-e h.5.5-end nd + C Ch.18 h.18 all) Question 1: You have a large balloon containing 1.0 mol of gaseous water vapor at 70 °C. How will the following step affect the internal energy of the system? s ystem? A)  The temperature of the system is raised to 100 °C.  -  -  - 

The internal energy will decrease. The internal energy will remain unchanged. The internal energy will increase.

at – 20 20 °C.  B)  The vapor is frozen to a solid, at – 

- The internal energy will decrease. -   The internal energy will remain unchanged. -  The internal energy will increase.

 

  VISUALIZATION Heat and Work I

Question 2: When a system gains energy that energy can be used to do a number of things. It can increase the temperature of the system, it can cause a phase change, or it can perform work. Watch the animation here of two systems involving the sublimation of solid carbon dioxide and answer the questions that follow. The upper animation shows a few of the molecules of carbon dioxide diox ide when dry ice is sealed in a flexible plastic p lastic bag. The lower animation shows carbon dioxide molecules sealed in a rigid, stoppered container. In both animations the temperature of the carbon dioxide increases.  1.  Watch the animation of sublimation of CO 2 in the sealed flask. Is there any an y movement of the flask or any object outside the flask? -  Yes -   No 2.  Is any work done during the sublimation of CO2 in the sealed flask? -  Yes -   No 3.  What is the relationship between the quantity of energy e nergy transferred into the flask, flask, E   E iinn, and the change in energy of the contents of the flask, Δ E ? -  Δ E  = E   = E in in 

 

in  Δ E   E   E   E in --  Δ   > E  in 

4.   Now examine the CO2 expanding in the plastic bag. Is any work done by this system? -  Yes -   No 5.  For the plastic bag, what is the relationship between the quantity of energy transferred into the bag, E  bag, E in in, and the change in energy of the contents of the bag, Δ E ? -  Δ E  = E   = E in in  in  -  Δ E  > E   > E in

 

-  Δ E