Typically the smaller the step size and the longer

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: eriodic box”; I will run this one in vacuo, however, since it often becomes difficult to see the molecule with a lot of water molecules around it. Step one is complete; the calculation has been set up. Now, step 2; run the calculation. Go to “Compute” and “Molecular Dynamics”; Hyper Chem will remember your choices from the previous step. For example, my MD will run using the AMBER force field. You will notice there are more choices here, such as step size and time of simulation. Typically, the smaller the step size and the longer the run, the more accurate the results, but the slower it will be. For our purposes, I recommend simply choosing the results. You will see the isopropanal begin to dance on your screen; this is a simulation of how the molecule can be expected to actually move, if we could see it so clearly, in reality. Dakota State University Page 33 of 232 Using HyperChem General Chemistry I and II Lab Manual Now, aside from the really cool ways the molecule moves, there is not much more that we need here today. However, while this simulation was running, there were certain properties that were calculated as it ran. Although we don’t need them now, if you want to display these properties (the third and final step of the sequence), go to “compute” and you will see several options that were not available before (such as “properties” and “plot molecular graphs”). Feel free to take a look at what is in these if you are curious. Dakota State University Page 34 of 232 Basic Laboratory Procedures General Chemistry I and II Lab Manual Basic Laboratory Procedures Laboratory Equipment: Most basic laboratory equipment is made of glass so one can easily see what is happening inside. When I think of the most common equipment, the beaker and the flask come to mind. Beakers are probably most commonly used; their wide mouth and spouts make it very easy to transfer solutions from one beaker to another. The flask (or, to be more precise, the “Erlenmeyer flask”) is an excellent choice to run reactions if you do not plan to transfer solutions frequently. The tapered neck of the flask makes it very easy to grab, hold, swirl and manipulate. Other pieces of common equipment includes the scoopula (for manipulating moderate sized amo unts of solids), the spatula (for smaller amounts of solid), The stirring rod and the rubber policeman (on the end of a stirring rod, for scraping crystals out of beakers). For this lab, we will replace the thermometer with a Pasco temperature probe. Rather than droppers, we will use disposable pipettes. Balance: The balance is used to determine the mass of an object. Like so many other things today, modern balances just continue to get easier to use. At DSU, we use digital balances. The basic operation of these balances is trivial; place your object on the pan, and the mass appears on the display. However, also like so many modern devices, there are advanced features that may not be so obvious. In this section, I will not only Dakota State University Page 35 of 232 Basic Laboratory Procedures General Chemistry I and II Lab...
View Full Document

This note was uploaded on 09/18/2012 for the course CHEMISTRY 1010 taught by Professor Kumar during the Fall '11 term at WPI.

Ask a homework question - tutors are online