Change is influenced by many different factors in many different situations. If you imagine the 400,000 gallons of water in a stream at the top of a hill, you can picture that they will flow down the hill in order to reach equilibrium. But what if the temperature outside is -40 degrees Fahrenheit? How might this change the movement of the water molecules down the hill?
This virtual lab will allow you to explore how temperature changes affect two linked systems. The demonstration uses red and blue balls to represent molecules. You will use the sliders in this activity to play around with speeding up and slowing down change within a system. Items that should be recorded for submission are written in italics.
Go to http://chemconnections.org/Java/molecules/index.html [->0]
Click once on the demonstration window once it loads - this …show more content…
may take a few minutes if you have a slow connection.
For both the Red side and the Blue side, move the slider labeled "Mass" all the way to the right (the value should read 199 amu). You should see the balls in the window above get larger. Each of these balls represents a molecule moving around inside a divided chamber. You can see how the molecules move around randomly until they bump into a wall or into each other.
Lower the temperature on the Red side of the chamber by moving the slider labeled "Temperature" all the way to the left (the value should read 1 K).
*Compare the movement of the molecules on the very cold Red side with the molecules on the Blue side. How does lowering their temperature change the speed at which these molecules move?
Now lower the temperature on the Blue side of the chamber to 1 K, the same way you did in Step 4.
Add lots more molecules to both sides by increasing the slider labeled "Number" all the way to the right (the value should read 99) for both the Red and the Blue side.
*How would adding more molecules affect the motion inside the chambers?
Click the "Remove Barrier" button and time how long it takes for the blue and the red molecules to mix completely (note: the button text may not appear on your screen. The "Remove Barrier" button is on the far lower right).
*Record this result as "Mixing at 1K"
Click the "Reset" button (note: the button text may not appear on your screen. The "Reset" button is just to the left of the "Remove Barrier" button). Then, repeat steps 3-6 above. Once you have 99 slow-moving molecules in each chamber, increase the temperature in both chambers to 999 K. You should see two very active chambers!
Click the "Remove Barrier" button on the lower right and time how long it takes for the blue and red molecules to mix completely.
*Record this result as "Mixing at 999K"
*In a paragraph, describe your results and explain the effect temperature appears to have on the equilibrium of mixing.
*Based on your virtual lab experiment, compare what would happen if you put a spoonful of honey into a cup of 200 degree Fahrenheit tea versus placing a spoonful of honey into an identical cup filled with 45 degree Fahrenheit tea.
*If you opened up a container of very stinky Limburger cheese at one end of an empty large outdoor parking lot with a group of shoppers about 50 feet away. Would you be able to enjoy eating your snack longer without offending the shoppers in the summer or the winter? Explain.
Observe the time it took for the red and blue molecules to mix at 999K.
Before clicking on the quiz link on the left to complete the quiz to receive credit for this lab, think about what you have observed in this virtual lab including the effect temperature appears to have on the equilibrium of
mixing.
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