Full Lab Manual
Introduction & Goals
Chemistry & Background
In Your Write-up
Complete your prelab before coming to lab lecture. This includes the objective, reference, three prelab problems, a complete procedure, and a sample calculation or analysis flowchart for the calculation of the theoretical and percent yield of the reaction.
In the Procedure section, your write-up should include observations of each step of the synthesis reaction and recrystalization. Record your observations during the course of the synthesis, including color changes, gas evolution, smells, and precipitation. Note any differences between your prelab procedure and what was actually done in the lab. Record the masses and volumes of all reagents to at least two significant figures. During waiting times, calculate the limiting reagent and theoretical yield for your reaction.
The Data and Results section should include a calculation of the theoretical yield of the preparation according to the net reaction stoichiometry and the molar quantities of the different reagents used. The calculation should clearly show how the reagent that limits the overall yield was identified. The yield of product should be calculated as a percentage of the theoretical yield. Relative yields are very low in this experiment, largely because of the substantial solubility of the product. The preparation should be considered a success if 0.5 g or more of good-quality recrystallized product is obtained. In this week's data sheet, you will report the crude yield of product, before recrystalization and drying. You will calculate the yield of recrystallized product next week, after your sample has dried. Your final grade for this week's lab will be recorded when your recrystallized yield is turned in with next week's lab. Include a description of each reagent used in the procedure in the synthesis reaction (acid-base, redox, common ion effect, precipitation, etc.). Relate this chemistry to your observations for the reaction. Include a description of each reagent used in the procedure and its purpose in the reaction.
Trustees of Dartmouth College, Copyright 1997-2011