Laboratorio de quimica stoichiometry

David Cartwright
LAB REPORT STOICHIOMETRY
Tables:
This table shows the amount of Calcium chloride, and of Sodium Carbonate that will be introduced in each test tube, with the concentration of each amount being 0.500M.
Test Tube number Amount of CaCl2 (+/- 0.05ml) Amount of Na2CO3 (+/- 0.05ml)
2 02.00 18.00
4 04.00 16.00
6 06.00 14.00
8 08.00 12.00
10 10.00 10.00
12 12.00 08.00
1414.00 06.00
16 16.00 04.00
18 18.00 02.00

This second table shows the weight of the filter paper before the experiment, and the weight of the filter paper after the experiment with the CaCO3.
Filter paper number Weight of filter paper before the filtration (+/-0.01 g) Weight of filter paper after the filtration (+/-0.01 g)
2 1.12 1.38
4 1.05 1.39
6 1.06 1.43
8 1.14 1.63
10 1.09 1.59
121.16 1.63
14 1.12 1.49
16 1.13 1.45
18 1.15 1.39

Weight of CaCO3:
Procedure- Weight of paper after the filtration – weight of paper before the filtration
1.38 – 1.12 = 0.26g for filter paper #2

Table showing the weight of the CaCO3 for its respective filter paper.
Filter paper # Amount of CaCO3 after procedure. (+/-0.02 g)
2 0.26
4 0.34
6 0.37
8 0.49
10 0.50
12 0.47
14 0.3716 0.32
18 0.24

This table shows a pattern in the amount of Calcium Carbonate left after the filtration, we can notice that the amount increases until filtration paper 10, where the amount reaches a maximum and then starts decreasing until it reaches 0.24 grams.

To make a graph about these results we first have to work out the mass using Stoichiometry, of the Calcium Carbonate with each ofthe different amounts used in the experiment, so that the experimental results can be compared with the theoretical results in a graph.
Procedure:
CaCl2 + Na2CO3 = CaCO3 + 2NaCl
02.00ml of CaCl2 / 1000 = 0.002 dm3 0.002dm3 x 0.5M = 0.001mol- Limiting reagent
18.00ml of Na2CO3/1000 = 0.018 dm3 0.018dm3 x 0.5M = 0.009mol- Excess reagent
Ca = 40.08 C = 12.01 O = (3 x 16) = 4840.08 + 12.01 + 48 = 100.09Mr grams = Mr x moles
Grams = 100.09 x 0.001 = 0.1grams of CaCO3
After the procedure we notice the difference in the values between the theoretical values and the experimental values with this procedure:
0.26/0.1 = 2.6 x 100 = 260%
This procedure is repeated for all the other trials with different amounts of reactants.

This table shows the theoretical valuesfor the grams against the experimental values we got of the grams, for each of the trials with different amounts. And also includes the percentage error that our experimental results had compared to the theoretical values.

Filter paper Theoretical values (g) Experimental results (g) Percentage Error (%)
2 0.1 0.26 260
4 0.2 0.34 170
6 0.3 0.37 123.3
8 0.4 0.49 122.5
10 0.5 0.50 100
12 0.40.47 117.5
14 0.3 0.37 123.3
16 0.2 0.32 160
18 0.1 0.24 240

The table shows that the experimental values that we got were very inaccurate, their percent efficiency was higher than a hundred percent in all the trials, but they do show the same pattern that the theoretical values show, with the maximum in the same trial.
This graph shows the variation in the mass (g) of the CaCO3 acordingto the amount of Calcium Chloride. The mass is shown for the theoretical values (blue line) and to the experiment results (red line).

This graph shows us that the pattern in the theoretical values and in the experimental results is the same, although the experimental values don’t represent a line as neat as the theoretical values, the pattern represented is the same and shows its peak at thesame trial. We can notice that the highest point in the graph, the peak in both representations is when the concentration of CaCl2 was 10.00ml, which was the trial where both solutions, Calcium Chloride and Sodium Carbonate had the same amount of volume mixed together, after this trial, when the amount of calcium chloride started to become bigger than the amount of Sodium Carbonate, we see a...