Include NY of the steps in which you may have lost sample or lost confidence in your technique. Write the complete balanced equation. Use subscripts correctly by using the tool bar or you will lose a point. (2 points) Calculations: (10 points) for all calculations show your work using a table to demonstrate the unit doctor method for full credit. Include the correct significant figures from your data. #1 has an example for you. Record all answers in the table below. 1. Calculate the number of moles of Cacao-OH from the mass you weighed out and record in the table below.
Have Factor (molar mass) Want g cacao;OH moles cacao;OH Note: Cacao;OH is an example off hydrate, the 2 water molecules are attached to the crystal structure of the compound. When determining the molar mass, add the mass of 2 water molecules to the mass of the Cacao. 2. From the balanced equation calculate the number of moles of Niacin required to react completely with the Cacao;OH and record in the table. (See lab, page 79 for example) Prepare a table. 3. Calculate the number of grams of Niacin to weigh out from the number of moles in step 2. Prepare a table. Calculate the number of grams of Cacao that are expected to be produced. This is your theoretical yield. Factor (molecular mass) Factor (mole ratio) _ g official,OH I mole Cacao;OH mole Cacao g cacao mole cacao;OH I mole Cacao g Cacao Fill in the data table. (3 points) Compound mass (g) (+1-0. 1 g) # of moles cacao-OH mass used Niacin mass used mass to filter paper Mass of filter paper and Cacao Mass of Cacao 1. Calculate the % yield from the number of grams of Cacao that are actually produced. Don’t forget to show your work. Conclusions: (3 points)
Did you accomplish your purpose? Restate the purpose and clearly state your results. Show the experimental errors in the procedure. E. G. Where are the places you may have lost or “gained” sample? Where do you think you could improve your yield? Write in paragraph format. Reflection: (2 points) You probably deal with “geochemistry” problems in your daily life but not necessarily on a molecular level. Discuss how “geochemistry is used in cooking sewing, or any other activity that results in a product. Do you have to worry about a “limiting reagent” or a “percent yield? ‘