I did a lab the other day where we separated a mixture of NaCl, SiO2, and CaCO3. The Mixture was made by my professor and we did not know the original amounts of each compound. After recovering all of the compounds we found that there was..
36.4% NaCl
36.4% SiO2
40.9% CaCO3
the total % recovered was 113.7% with a 13.7% error. I do not understand how we recovered more that the original sample. One of the post lab questions ask
1. List possible manipulation errors that might contribute to the following errors:
-obtaining a significant larger amount of NaCl than as present in the original sample;
-Obtaining a significant small amount SiO2 than was present in the original sample.
help me please! I thought maybe the physical form of the NaCl changed the mass after the boiling off process, I have also thought about the chemical bonding process, but it doesn't make an sense to me.
and 5.
It seems like you're trying to understand the possible errors that could have led to the observed results in your lab. Although I cannot know the exact details of your experiment, I can certainly help you understand some potential sources of error that might explain the discrepancies you observed.
1. Obtaining a significantly larger amount of NaCl than was present in the original sample:
- Contamination: During the separation process, it's possible that some impurities or other substances could have mixed with the NaCl, increasing its mass. This could occur if the equipment or containers used were not properly cleaned or if there was cross-contamination during the experiment.
- Mechanical losses: It's important to handle the substances carefully to prevent any accidental loss. If some NaCl was spilled or lost during transfer between containers, this would result in a higher measured mass.
2. Obtaining a significantly smaller amount of SiO2 than was present in the original sample:
- Incomplete separation: It's possible that some SiO2 remained mixed with other compounds, especially if the separation techniques used were not effective in completely isolating it. This could lead to a lower measured mass of SiO2.
- Experimental technique: If you were not thorough in your separation process or missed any steps, it could result in less SiO2 being recovered. Follow the separation techniques carefully to ensure accurate results.
Regarding your thoughts on the physical form of NaCl changing the mass after the boiling off process, it's less likely to be a major factor. NaCl is a stable compound that should not undergo significant changes in mass during the process unless there is some contamination or loss, as mentioned earlier. And regarding the chemical bonding process, in this case, it is mainly a physical separation of the different components rather than any significant chemical reactions occurring.
Remember, these are just possible explanations, and it's essential to evaluate the specific details of your experiment to determine the most likely sources of error.