Lab 6D Stoichiometry

Objectives:
To observe the reaction between solutions of sodium carbonate and calcium chloride
To determine which of the reactant is the limitng and which is the excess reactant
To determine the theoretical mass of precipitate that should form
To compare the actual mass with the theoretical mass of precipitate and calculate the percent yield

Supplies:
centigram
two 25mL graduated cylinder
beacker (250mL)
wash bottle
safety goggle
filtering apparatus
ring stand
250 mL funnel
filter paper
lab apron

Chemicals
25 mL of calcium carbonate
25 mL of sodium chloride

Procedure:
1. Put on lab coat and goggles
2. Get two 25 mL graduated cylinder and a 250 mL beaker
3. Measure 25 mL of calcium carbonate and sodim chloride and pour them each into the 25mL graduated cylinder
4. Combine the two chemicals by pouring them both into the 250 mL beaker. Wait for 5 minutes while observing what happens
5. Write your names on the filter paper and then weigh the filter paper. Set up the filtering apparatus with it
6. Use wash bottle to wet the bottom of the filter paper to keep it in place
7. Slowly stir the newly mixed chemical into the filter as it filters the liquid into the beaker. This will take a while so be patient.
8. Once all filtered, take the filter paper our and place it on a paper towel to dry.
9. Remember to clean up and wash your hands once you are done on day one of the experiment.
Day 2:
Weigh the precipitate left over from day 1.

Follow-Up

We measured the amount of CaCO3 produced by our experiment in grams with a centigram. Then, after balancing the equation "1Na2CO3 + 1CaCl2 ---> 2NaCl + 1CaCO3" we calculated the percent yield for our experiment.

The theoretical yield for CaCO3 is 1.15125 grams = 1.3grams.
The actual yield for our experiment was 1.18 grams.
So the percent yield is (1.18/1.125125) x 100% = 94.3%