Wednesday, December 30, 2009

Thursday, December 24, 2009

Oh, the weather outside is frightful

This is shaping up to be a Christmas to remember for us Midwesterners. After getting almost 8 inches of snow last night, the second wave has just started. We can expect to get 10-12 more inches by Saturday. I'm running out of places to put all of this snow. My driveway is bordered by a 3-4 foot wall of snow. The kids love it.

Thankfully, we have no travel plans, we have a pantry full of food, and I have plenty of beer. Unless our roof collapses from the weight of the snow, we will just hunker down and wait it out... while drinking beer. At least I will.

Merry Christmas everyone.

Monday, December 21, 2009

Something for free

Recently, I was doing a bit of research on the proteins responsible for beer foam. I plan on writing a post about that sometime soon.[1]

This journal is a treasure trove of articles dealing with everything from PCR analysis of bacterial infections, to GC-MS analysis of yeast metabolites, to SDS-PAGE analysis of beer proteins.

And best of all, the Journal can be accessed free of charge. At least temporarily. I have no idea how long access had been free nor do I know how long it will last, but I've been taking advantage of it. There's some good stuff there.

They provide access back to 1990, but they also have thrown in a volume from 1896. I like the articles that reference Louis Pasteur's latest discoveries.

[1] yeah right. I've heard that before.

Tuesday, December 15, 2009

And I call myself a chemist

I hate it when I do things that #1 result in the destruction of my toys and #2 are a direct result of me not applying sound chemical principles to the task at hand.

A few days ago I was going to rack 4 different beers. To do so, I needed to clean and sanitize an empty carboy. The empty carboy was sitting on my basement floor. The outside temperatures are currently around 0°F here in Minnesota and anything on my basement floor is around 50°F, including the aforementioned carboy. I placed the carboy in my utility sink and turned the water on. I only turned the hot water on. My intent was to turn the hot water on, get the sanitizer, turn the cold water on and start sanitizin'. Before I got a chance to turn the cold water on, I heard the most terrible and unmistakable sound. I can't really describe what it sounded like. It was more of a pop that a shatter sound, but I knew exactly what had happened. My carboy was dead.

The hot water on the cold carboy shattered the bottom of my 6.5 gallon glass carboy. It was irreparable. Thankfully, the whole thing remained intact enough for me to lift the whole thing into the garbage can and get it outside without getting glass everywhere.

I should have known better.

Science section:
Glass primer. So, what is glass? Why did the carboy shatter?

Glass is an amorphous solid composed of silica (SiO2). That's right. I said "solid," Contrary to popular belief, glass is not a "highly viscous" liquid. It is an amorphous solid meaning it is a solid that does not have an organized crystal structure.

The primary glass making material is SiO2, but this silica is not that great for making glass. It has a high melting point (1723°C) and is highly viscous when molten. That makes it difficult to work with. To make the silica more useable, chemicals known as fluxing oxides are added. These fluxes can affect the properties significantly and are responsible for the different types of glass.

Soda-lime glass is the most common type of glass and the type that was used in my carboy. This glass is also found in windows. It is made by mixing sodium oxide (soda, Na2O) and calcium oxide (lime, CaO) with the silica. This does two things. First it lowers the melting point of the glass to around 1300°C. That makes it much more workable. The soda and lime also make the glass more robust and resistant to corrosion. However, soda-lime glass has a high coefficient of thermal expansion. That means it expands significantly when it gets hot. Inconsistent expansion can create stress points and result in cracks. This can be demonstrated very well using the cold carboy in hot water trick!!!

Borosilicate glass is much more thermally robust. It is made by adding boron oxide (B2O3), among other things, to the silica. The boron oxide also reduces the melting point, but more importantly,it also reduces the thermal expansion significantly and makes the glass highly resistant to cracking as a result of temperature changes. Any glass you use for cooking is borosilicate glass. Pyrex and Kimax are two brand names. Science glassware is almost always borosilicate glass. My carboy was NOT made of this type of glass.

There are other types of glass, but these are the most common.

Saturday, December 12, 2009

He should but won't

Ndamukong Suh should win the Heisman trophy, but he probably won't. Even after manhandling a fellow Heisman finalist in the Big 12 Championship game (see above), that may not be enough to push him over the top. The Heisman Trophy is essentially an offensive player award.

Wednesday, December 9, 2009


There are not enough 'WTFs' for this one.

A chemistry student in the Ukraine was found dead with his jaw blown off by what is believed to be exploding chewing gum, according to reports.

It gets a bit more interesting:

The student apparently had a bizarre habit of chewing gum after dipping it into citric acid, Russian news agency Ria Novosti said.

Officers found both citric acid packets and a similar-looking unidentified substance, believed to be some kind of explosive material, on a table near the body, the agency continued.

Investigators suspect that the student simply confused the packets and put gum covered with explosive material into his mouth.

WHAT THE HARTREE-FOCK!!!!!! What did have sitting next to his citric acid that was capable of blowing his jaw off?

This blows

We are having a bit of a blizzard blow through our neck of the woods. The blizzard of aught-nine has descended upon us. Every school around here is closed.

I cleared the snow out my driveway using my grandpa's old snowblower. The thing is from the late 60's, it is big and it still works like a charm. There are zero safety features, but boy does it blow. The way my neighbor's house is aligned with mine causes the wind to blow all of his snow into a huge drift on my driveway. His whole front yard is nearly void of snow. It's all on my driveway. So, even though we only had about 8 inches of snow, I have a 3 foot drift across my driveway. Until this year, I was a one man shoveling crew. It would take me a few hours and several asthma attacks to clear it away. But, with this snowblower, I got rid of that thing in about 30 minutes with a lot less effort.

I made it to my office around noon. Since classes were cancelled, I'm getting a lot of things done since I don't have all of those pesky students bothering me.

Tuesday, December 8, 2009

Here's a problem for you

When I took over this teaching gig, my predecessor left a fold behind labeled "Diabolical Organic Problems." I love the word "Diabolical" but some may argue that that title is redundant with "Organic."

I have on occasion given my students diabolical problems to hone their skills. Today in preparation for the cumulative final exam, I gave my General Chemistry class the following question:

A 21.0 cm3 piece of dry ice is placed into a sealed 5.0 L container at STP. The dry ice is allowed to sublime while the temperature is held constant at 0°C. The container also contains 12.7 grams of sodium hydroxide. Sodium hydroxide reacts with carbon dioxide to form solid sodium carbonate and liquid water. What will the volume of the dry ice be when the pressure in the container is 2.5 atm? The density of dry ice is 1.5 g/cm3. Assume the volume of the container is 5.0L.

I'm kind of proud of this question as it incorporates several concepts we covered in the first half of the semester. I'll give anyone who answers this 50 extra credit points.