The reactions that you carry out in the laboratory section are set up in a scale that you get enough material to carry out its characterization if you have a decent yield. However, if you upscale or downscale reactions, you need to keep several things in mind:

1. If you upscale reactions, make sure that you also upscale the equipment used. Often times, the reaction is more violent and much more difficult to control and does not necessarily afford much more product.The reaction also requires more time to complete.

2. If you downscale the reaction, you can run into the problem that you might lose a significant amount of the product during the transfers. A common mistake among students is the use of a (big) Buechner funnel while processing a minute amount of precipitate. It surely goes faster to filter the solution, but it will also be very difficult to get the product off the filter paper without contaminating it with the fibers of the filter paper.

3. If you have to up or downscale reactions in general it is most important to maintain the appropriate ratios of your compounds directly involved in your reaction e.g. the procedure asks you to react 5 g of compound A with 3 g of compound B and 1 g of compound C (which is the catalyst) in 50 mL of solvent. If you start with only 3 g of compound A, you would only need 1.8 g of compound B and 0.6 g of compound C. The amount of solvent should be around 30 mL.

4. Whenever you start a reaction, you should ask yourself the following questions:

a. How much of the product do I expect assuming 100% yield (For most of your reactions, a yield of 80% is more reasonable!)?

b. For which chemicals in my reaction is it important to be accurate in my measurement? Where is an approximate amount good enough e.g. solvents, compounds used in a large excess already, etc?

c. What are the byproducts of my reaction? Is there an evolution of gases that require a more controlled reaction and bigger size glassware?

d.