Diagram of Apparatus:
Data Collection and Processing
Raw Data Tables
Table 1: Trial 1
Table 2: Trial 2
Table 3: Trial 3
Observations
1. The beaker with 3.0M HCl reacts more violently with the CaCO3
2. Bubbles are produced during the reaction
3. No indication of reaction releasing heat
Data Processing
Overview
Using values in the 2nd and 3rd column in Tables 1-3, I will calculate the yield of CO2 in each trial.
The theoretical yield of Carbon dioxide in the reaction is as follows:
Using this value I shall calculate the percentage yield in each of the above trials.
Sample Calculation: Percentage yield of Carbon dioxide
Table 4: Yield and Percentage Yield of CO2 in 3.0M HCl
Table 5: Yield and Percentage Yield of CO2 in 2.0M HCl
Table 6: Yield and Percentage Yield of CO2 in 1.0M HCl
Conclusion and Evaluation
When examining the Percentage yield value in the 2nd rows of Tables 4-6, the values are 44.2%±0.7%, 45.2%±0.7%, and 45.5±0.7% respectively. I notice that it seems to increase with the lowering concentration, but I do not see a big variation in values. This is also the case for the 3rd and 4th rows. Taking into account the uncertainty values in each trial, and since I only have 3 trials at my disposal, I cannot conclude that lowering concentration increases percentage yield. Thus, the data present leads me to conclude that the concentration of HCl has no effect on the percentage yield of CO2.
However, upon closer examination of my experiment, I noticed that in the reaction, the yield of CO2 only depends on the amount of CaCO3 involved, and has nothing to with HCl, or the concentration of it, to begin with. To improve this I will calculate the percentage yield of CaCl2 instead of CO2.
Other aspects to take note of in the experiment include: making sure the amount of CaCO3 is precisely 3.0g, making sure to use the same stirring rod for each beaker, and being more precise in measuring out HCl.
Modified Procedure:
- "Mark each of the 3 beakers with '2.0M', '1.0M' and '0.5M' respectively"→"Mark each of the 3 beakers with '3.0M', '2.0M' and '1.0M' respectively"
3. → "Measure out 3 beakers of 50mL of HCl, add 25mL of water into the 2.0M beaker, and 100mL of water into the 1.0M beaker to dilute the acid"
4. →"Place 3.0g of Calcium carbonate in each of the 3 beakers, agitate the mixture with a stirring rod until bubbles do not form anymore"
7. Repeat steps 1-6.
