This week in General Chemistry lab, the students were experimenting with volume, pressure, and temperature. The equipment they used involved a 3-way valve. I have discovered that 3-way valves are very confusing to a lot of people, even when they have a podcast that explains it very well. On top of that, the lever that turns has an arrow and the word OFF printed on it. Common sense (and the podcast) should kick in and tell you that wherever the lever is pointed is the direction that is turned off. Well, some people just don't get it. Here's a conversation I had this week.
Lab girl: "Nothing is happening here. No matter what we do, the pressure stays the same."
Me: "Ok, let's look at your set up here." Me thinking: Of course the pressure is staying the same, you have the valve turned to where OFF is pointed toward the pressure sensor! But of course we want the students to try to figure things out, so I try to help a little: "Take a look at your 3-way valve and tell me why you have it set the way it is."
Lab girl (not even looking at the valve): "I don't know."
Me: "Ok, do you know what the blue lever is doing?"
Lab girl: "No."
Me: "What does the blue lever say on it?"
Lab girl (not even looking at the lever): "I don't know."
Me thinking: LOOK at the lever and READ what it says!!!
Me: "Look at the lever. What does it say?"
Lab girl: "Oh! OFF!"
Me: "Yes! Now, why isn't your pressure reading changing?"
Lab girl: "I don't know."
Me: "What is turned OFF right now?"
Lab girl: "The valve?"
Me (I've lost all hope for this girl at this point): "The valve is turned OFF toward the sensor right now. That means that no matter what you do to the rest of the system, the sensor is not detecting the change because the valve is closed in that direction."
Lab girl: "Oh!! So, do I need to change that?"
This could be an interesting semester!
On another note, I am sitting in on the Gen Chem lectures this fall. I never actually took this class because I started out an animal science major, and they take a different entry level Chemistry class. So, I may have some good quotes from class this semester too. So far, I've just observed how little algebra they know. It's sad really.
One funny thing did happen this week though. Some kid walked in right before class started and looked totally lost. After several seconds of confusion, he said, "Oh, I think I'm in the wrong class." This is the THIRD week of class! Really, he should know where his classes are by now. AND he's not even a freshman. Oh, speaking of freshman, I have a good first-day story to tell. I'll save it for next week :)
And finally, this is for Shelly, courtesy of the West Texas Fair and Rodeo that we went to last night. I thought you might like this! (Shelly loves animals snoots)