Wednesday, July 19, 2006


It was the same night that my study group member wanted to use the Peng-Robinson equation to solve the problem involving carbon dioxide. We had been working on Thermo II homework for hours and hours, and we were getting way too punchy to keep it up. So we decided that, finished or not, we would stop working at midnight.

Sure enough, when 11:59 pm rolled around, not much was getting accomplished as each of us sat and stared at the clock waiting for the magical witching hour.

At 11:59:45, the clock stopped.

Then the second hand started to sweep backwards.

We left anyway.


Doktah said...

You kept bringing it up. If i don't say something I'm going to explode... If you are working with carbon dioxide, unless it's at ungodly high pressures or low temperatures, assuming an ideal gas will only introduce a few percent error. It's not like it's ammonia or something. C'mon.

Mo said...

That was my point. I was not the one who wanted to use the Peng-Robinson equation. I was all about the ideal gas law. Our study group had a minor argument about it on more than one occassion, and I was always on the side of using PV=nRT. Because, Peng-Robinson? For one problem in a homework set that was not specifically about Peng-Robinson? Not likely.

Banalities said...
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Banalities said...

My high school AP Chem teacher, who was one of the best teachers I ever had, was a big fan of mnemonic devices. For example, when we were learning orbitals, he gave us 'Stoneham Police Don't Find Grass Hiding In Kitchens'. (The weekend after the cops busted a pot dealer in Saugus, he showed us the news clipping and informed us that for accuracy's sake, 'Saugus Police *Do* Find Grass Hiding In Kitchens'.)

Anyway, when we were doing ideal gases, someone asked if he had a similar mnemonic device for PV=nRT. He thought for a second and said, "Yeah. Pivnurt."

Mo said...

I tell you what, Banalities, after four years of Chem E classes, you don't need a mnemonic device to remember PV=nRT. It becomes a mantra. I can still remember that R=8.314 J/mol*K, and I haven't used PV=nRT in about 8 years.