There are two versions of each lab, one with a ten-question conclusion and one with directions for a full lab report. This way the teacher has the option! Each lab is two pages to allow for one two-sided handout.
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“[S]traight forward, to the point, using household chemicals…this is the lab book for you.
I teach high school chemistry and this is exactly what [I] was looking for. Labs included simple household chemicals that could be easily found. Nice format, easy to follow along procedures, and touches on every topic of our chemistry curriculum.”
You can buy this lab book for $23 at amazon.com or lulu.com. It will take 1-2 weeks to get to you -- Order Now. It’s a great resource!
*Some of you have already purchased my lab book – be sure to check out Page 141 !
“Scientists in supramolecular chemistry often run into surprising outcomes. A broken seal of a lab cuvette led an American researcher at the Eindhoven University of Technology to the origin of these inexplicable results: the weather. Or the humidity, to be more precise, because this determines the water concentration in oils used as solvents, which was previously thought to be negligible. Research now shows that the lone water molecules in oil aren't just spectators, they firmly direct supramolecular processes. This outcome means that a lot of previous research has to be re-examined, but also that chemists get a new, cheap and powerful tool. “
“In September 2016 postdoctoral researcher Nathan van Zee spent a week with his parents in Florida. But his thoughts often led him back to his lab in The Netherlands because he had been struggling for quite some time with erratic outcomes he didn't understand. The molecular helices that he was synthesizing sometimes had a clockwise structure and sometimes an anti-clockwise structure. …
After his flight back from the US he immediately went to his laboratory to start a new experiment, after which he wanted to take a nap. But his jetlag caused him to use the wrong settings for the instrument, and he overslept. His eureka moment … came the next day. Back in the lab he saw strange results. But he also saw that the seal of his lab cuvette was broken, and the ultradry air of the enclosing sample holder had gotten into it. This gave him an important clue: his sample had become drier, suggesting the water content of the solvent oil is a driving force.
Van Zee and his supervisor professor Bert Meijer immediately knew they were on to something important, and they decided to get to the bottom of it. They discovered that it was indeed the water concentration in the sample that made the difference, even though it was only a few ppm (parts per million). Even with extremely small fluctuations in water concentration, they observed that the helix rotation changes from clockwise to anti-clockwise.
This result caused the researchers to have a closer look at some of their previous work that had inexplicable results. It turned out that also in these tests the water concentration determined the outcome. The previously inexplicable changes in the results were caused by fluctuations in the water content of the oil-based solvent. Because that content fluctuates with the humidity. And the atmospheric humidity—indoors and outdoors—is constantly changing because of the weather. The consequence is that a test run on day A can have totally different results from exactly the same test run on day B.”
“Research now shows that the lone water molecules in oil aren't just spectators, they firmly direct supramolecular processes. This outcome means that a lot of previous research has to be re-examined, but also that chemists get a new, cheap and powerful tool.”https://www.sciencedaily.com/releases/2018/05/180530144142.htm
“Water molecules are polar: one side is negatively charged and the other positively. That's why they like to bond, via so-called hydrogen bonds. But oil is hydrophobic: it repels water. This repulsion leaves too little space for the water molecules in oil to bond with other water molecules; they are isolated. That means their potential energy to form new hydrogen bonds is available for other uses. The Eindhoven researchers have shown that this energy of water plays a crucial role in the formation of supramolecular structures. These are molecular aggregates based on reversible bonds, for example hydrogen bonds.
Their findings put quite a burden on their own science field as well as adjacent ones. A lot of chemistry is done in oil, so a lot of previous research will have to be re-evaluated to assess the effect of water. The researchers suspect that many previous reports of unexplained phenomena, be it changes in structure, size or processing, are fundamentally due to interactions with water.”
Past blog posts that may be useful are:
03/12/2014 Polarity and Intermolecular Forces
03/16/2014 Dipole-dipole forces, etc.
Current scientific research can be useful as the basis of Essay or Short-Answer questions in your Final Exam.
Past “End of School Year” blog posts include:
06/08/2014 Final Exams – End of Year Preparation
06/15/2014 End of Year Activity – Lab Clean-Up
06/04/2015 Final Exams II
*This Blog contains several entries that would be helpful to your chemistry classroom. Check out the Topic List to help you to find past Blog entries.
Also, Write To Me about your successes, challenges, or questions in the Chemistry Classroom.
Remember, buying a copy of the lab book Chemistry on a Budget can be very useful to your Chemistry classroom with labs and class article ideas.
Have a great weekend!