For a two-solvent recrystallization, you should have one solvent (solvent #1) in which your desired compound is soluble at the boiling point. The second solvent(solvent #)should induce crystallization when added to a saturated solution of your compound in the primary solvent. Reference:

Thin Layer Chromatography (TlC) is an extremely useful technique for monitorin reactions. It is also used to determine the proper solvent system for performing separations using column chromatography. tLC uses a stationary phase, usually alumina or silica, that is highly polar(standard) or non-polar(reverse phase). The mobile phase is a solvent whose polarity you will choose. In 5.301, and in most lab

Overview: A good 'H NMR sample contains about 10 mg of compound. The solution should contain no solids or paramagnetic impurities. Your deuterated NMR solvent should be free of water,and your NMR spectrum should contain no solvent peaks. Reference: Zubrick page 295 is relatively useful, but you should follow the specifics in this handout Also, keep in mind that we won't be running continuous wave spectrometers, so you should disregard any discussion of them. NMR Solvents:

Flash column chromatography is a quick and (usually) easy way to separate complex mixtures of compounds. We will be performing relatively large scale separations in 5.301,around 1.0 g of compound. Columns are often smaller in scale than this and some of you will experience these once you move into the research lab. Column chromatography uses the same principles

Introduction Are people unaffected by tax increase if they pay zero in taxes afterwards? No, consumption may have changed in response to the tax increase Bundle consumed is less desirable Excess burden is a loss of welfare above and beyond the tax revenues collected

In this lecture, we consider the problem of a body in which the mass of the body changes during the motion, that is, m is a function of t, i.e. m(t). Although there are many cases for which this particular model is applicable, one of obvious importance to us are rockets. We shall see that a significant fraction of the mass of a rocket is the fuel, which is expelled during flight at a high velocity and thus, provides the propulsive force for the rocket

In this lecture, we will consider how to transfer from one orbit, or trajectory, to another. One of the assumptions that we shall make is that the velocity changes of the spacecraft, due to the propulsive effects, occur instantaneously. Although it obviously takes some time for the spacecraft to accelerate to the velocity of the new orbit, this assumption is reasonable when the burn time of the rocket is much smaller than the period of the orbit. In such cases, the Av required to do the maneuver is simply the difference between the

How Might a mouse search a Maze for Cheese? heese · State Space Search? As a Constraint Satisfaction Problem? Goal-directed Planning As a rule or production System? What is missing? Ideas in this lecture Objective is to accumulate rewards rather than goal states Task is to generate policies for how to act in all situations rather than a plan for a single starting situation

Entries Main entries in bold type Additives Beetroot Adenovirus. see viruses Benzo(a)pyrene quinone flatoxin. see moulds Blackberry, see beries Blackcurrant see berries Itermaria, see Moulds

Broadcast Routing Route a packet from a source to all nodes in the network Possible solutions: Flooding: Each node sends packet on all outgoing links Discard packets received a second time Spanning Tree Routing: Send packet along a tree that includes all of the nodes in the network