|Table of Contents for Caveman Chemistry: 28 Projects, from the Creation of Fire to the Production of Plastics|
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A: 56 grams of quicklime.
Once again, you can compare the theoretical and experimental yields from your lime-burning experience. Be alert for the possibility that your limestone was impure or your calcination incomplete.
A: 32 grams of water.
A: 132 grams of slaked lime.
Q: When cellulose is heated in a reducing environment it becomes charcoal as shown in Equation 1-1. How many grams of charcoal can be produced by the complete conversion of 100 grams of cellulose?
A: 40 grams of charcoal.
Q: The partial calcination of gypsum produces plaster according to Equation 10-1. How many grams of plaster can be produced by the complete conversion of 100 grams of gypsum?
A: 84 grams of plaster.
A: 5.1 grams of copper. Of course, you can go further and ask how many grams of tin will be produced by the complete reduction of 2 grams of tin oxide; the theoretical yield of bronze can then be had by adding those of copper and tin. The usual conditions apply; perhaps what you thought was pure copper carbonate was actually pure or impure malachite, a hydrate of copper carbonate; perhaps more than one reaction was going on in the kiln; perhaps you were unable to collect all of the metal produced; perhaps charcoal was the limiting reagent and consequently you have some un-reduced ore and less metal than you would expect. When the theoretical and experimental yields agree, however, you get that happy feeling that you understand what is going on and that all is right with the world.
Tape your stoichiometry quizzes into your notebook and calculate the theoretical yield for one of your previous projects: pottery, lime, gypsum, or metal. Compare the theoretical yield to your experimental yield. Speculate on the kinds of things that could lead to any discrepancies.