Chemistry Demonstrations Extraordinaire

Okay, maybe extraordinaire was a bit of an unrealistic term, but we have begun the study of gases in chemistry class, so I've decided on a couple of demonstrations to share with the class. Thought you might enjoy knowing that there is occasionally an ounce or two of fun in being a chemistry graduate student, contrary to popular belief.

1st Demo: This is actually for the previous chapter on thermochemistry (the transfer of heat energy from one system to another). I've decided to share an endothermic reaction (one that requires heat energy to "go" thus making the container feel cold - and example would be ammonium nitrate dissolved in water - this is what is in an athletic "instant cold pack"). I'll give a student two vials, each with a different solid. One has ammonium thiocyanate and the other has barium hydroxide octahydrate (doesn't matter if you don't have a clue what these are). What's cool is that when the students mix them together in one vial, they will begin to melt and dissolve into one another, and the vial will get extremely cold (below the freezing point of water), and actually cold enough to freeze the vial to a waterlogged piece of wood...can't wait to try it.

2nd Demo: Demonstrating the fact that increasing the amount of gas in a balloon will cause the volume to increase. Okay, this sounds incredibly obvious and mundane (and it is), but it will be cool because I will weigh out different masses of dry ice (solid CO2) and place them in an empty balloon and tie the balloon. The balloons will then inflate on their own as the CO2 sublimes, and we will be able to predict the volume of the gas in the balloon from the mass of the dry ice - and then check our calculations by actually finding the volume of the balloon. This is done by dunking the balloon in a completely full-to-the-brim bucket of water so that the water that spills out is collected and measured and that will be the volume of the balloon...very cool indeed.

3rd Demo: Demonstrating the fact that decreasing the temperature of a gas will decrease its volume. This was is great because I will have a student come up and inflate a balloon and tie it off. Then, once inflated I will have them place it is a styrofoam cooler and I will pour liquid nitrogen (T = 77 K = -196 deg C = -320.8 deg F) on the balloon and it will shrink (the gases will condense to a much smaller volume (and many will actually change to liquids when they are that cold). Pulling out a small, shriveled balloon, I will lay it on a table, and then as the balloon warms, it will re-inflate! It will be spectacular I'm sure.

Hey, I can't help it if I get excited about this stuff, I'm a dork.

Desensitization Training I

So, Frosty our dog has become more and more anxious and nervous as the days have gone by, even to the point where we were considering adopting a cat to keep him company during the day. Well, after a "house-visit" from the shelter, where essentially a cat comes over to our house for a couple of hours to see if it interacts well with Frosty, we were sure that was the answer. Thomas the Alley Cat was fun, playful, very friendly with us, and very friendly with Frosty. Frosty even liked him, so were set.

The more we thought about it, the more hesitant Mary-Jane and I were to adopt Thomas. We weren't sure how it would work out in the long term, and we were concerned with even if it did work for awhile, "What if eventually Frosty went nuts when we were gone after he was bored with the cat". We didn't want this to be a band-aid solution, so we have postponed any cat adoption...for now.

Instead we are trying something called "desensitization training" which is supposed to help dogs with separation anxiety. This training consists of repeatedly doing things that we commonly do right before we leave that would make Frosty nervous. What it boiled down to was Mary-Jane and I putting on our coats and taking them off, putting on our shoes and taking them off, and grabbing our keys and putting them back down over and over again for about 1.5 to 2 hours. Needless to say WE were definitely desensitized to the procedure, and Mary-Jane joked that Frosty would probably develop hip dysplasia before any desensitizing happened, but in reality, he seemed to become a bit more calm and used to it as time went on.

I'll keep you updated...

Dog vs. Door

I'm not sure if anything else really needs to be said other than the title and that the fact that the dog won.

But either way, I'm happy to recount this incident anyway :)

Currently on Wednesday evenings, M-J and I have been playing volleyball in Coralville with some of our friends here in Iowa. Along with this has come a recent anxious streak from Frosty when we are gone in the evening. He has gotten comfortable (for the most part) with us being gone for the day at work, but if we come home and leave again, then he usually has some issues (gnawing at the door, chewing on my rubber boots, etc.).

One particular Wednesday evening M-J came home from school, fed Frosty, walked him, and then had to put him back in our unfinished part of the basement because our friends Tyson, Sarah and Ben were coming to pick her up for volleyball (I just stay in Iowa City and meet them after work to save on a trip back to Williamsburg). He barked as they left, which was the norm, and they made it into Coralville for the game, only to meet me there and learn that our game was cancelled due to a broken sewer line in the Rec Center (which we were not previously told about). We decided to head back home and then meet at the Berbs to hangout and play games, so ventured back toward Williamsburg to pick up Frosty and be on our way.

To keep this in perspective, it had been about an hour and fifteen minutes from the time M-J left Frosty and when we got back home, and when we pulled in the driveway, we heard Frosty barking and saw him standing in the window of the front door. I exclaimed to Mary-Jane, "did you remember to put him up?!?!" She assured me yes, and then I was really worried. I went in and headed straight downstairs to have my fears realized. Our dog had broken through the door that separated the unfinished and finished portions of our basement to head upstairs and wait for us. We got after him, but it was difficult; a swirling set of emotions beset upon us as we were dealing with intense frustration, awe at the destruction, and a smidgen of pride for our dog's ability to conquer the barrier. Either way, thankfully it was a relatively inexpensive, hollow core door that we can replace with little trouble, but I'll try to post pictures soon so you can enjoy the sight of the destruction that we were met with when

we got home.

Needless to say, we are currently exploring ways to help him be more calm when we are gone, and have began with some desensitization training. I'll keep you updated on whether or not that works...until then, enjoy the door carnage.