Exp 10 Stoichiometry Lab Reportnew
Lab Report for Experiment #10
Stoichiometry of a Precipitation Reaction
Student's Name ____________________
Date of Experiment ___________
Date Report Submitted _________________
Title:
Purpose:
Instructor Changes: Weigh out about 1.7 g of CaCl2·2H2O and record your mass to +/- 0.1 g (for example 1.6 g, 1.7 g, or 1.8 g). We have made this change so that you will have 2 sig figs in subsequent calculations.
Have you made any changes to the procedure? Please explain:
Data Tables and Observation: Fill out the data sheet (below) for the experiment and submit with this form. Take careful notes during this experiment. Include any 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 factor 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 CaCl2·2H2O from the mass you weighed out and record in the table below.
Have
Factor (molar mass)
Want
_____ g CaCl2·2H2O
___ moles CaCl2·2H2O
Note: CaCl2·2H2O is an example of a 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 CaCl2.
2. From the balanced equation calculate the number of moles of Na2CO3 required to react completely with the CaCl2·2H2O and record in the table.
(See lab, page 79 for example) Prepare a table.
3. Calculate the number of grams of Na2CO3 to weigh out from the number of moles in step 2. Prepare a table.
4. Calculate the number of grams of CaCO3 that are expected to be produced. This is your theoretical yield.
Have
Factor (molecular mass)
Factor (mole ratio)
Stoichiometry of a Precipitation Reaction
Student's Name ____________________
Date of Experiment ___________
Date Report Submitted _________________
Title:
Purpose:
Instructor Changes: Weigh out about 1.7 g of CaCl2·2H2O and record your mass to +/- 0.1 g (for example 1.6 g, 1.7 g, or 1.8 g). We have made this change so that you will have 2 sig figs in subsequent calculations.
Have you made any changes to the procedure? Please explain:
Data Tables and Observation: Fill out the data sheet (below) for the experiment and submit with this form. Take careful notes during this experiment. Include any 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 factor 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 CaCl2·2H2O from the mass you weighed out and record in the table below.
Have
Factor (molar mass)
Want
_____ g CaCl2·2H2O
___ moles CaCl2·2H2O
Note: CaCl2·2H2O is an example of a 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 CaCl2.
2. From the balanced equation calculate the number of moles of Na2CO3 required to react completely with the CaCl2·2H2O and record in the table.
(See lab, page 79 for example) Prepare a table.
3. Calculate the number of grams of Na2CO3 to weigh out from the number of moles in step 2. Prepare a table.
4. Calculate the number of grams of CaCO3 that are expected to be produced. This is your theoretical yield.
Have
Factor (molecular mass)
Factor (mole ratio)