DRAFT: This module has unpublished changes.

Data Analysis:

Procedures:

 

Unknown solutions:

 

We can conclude that the anion present in Unknown Solution #1 was Chloride.

We cannot draw an accurate conclusion for Unknown Solution #2, given the anomalous results for procedure 2, and the premature disposal of the supernatant needed. We can however conclude that it contains either Phosphate and/or Sulfate.

 

Conclusion:

The goal of this experiment was to determine the anions present in a solution or mixture of solutions via qualitative analysis (a means for determining the chemical composition of an unknown substance by systematically reacting the unknown substance with a number of different reagents).

 

We can conclude that the anion present in Unknown Solution #1 was Chloride.

We cannot draw an accurate conclusion for Unknown Solution #2, given the anomalous results for procedure 2, and the premature disposal of the supernatant needed. We can however conclude that it contains either Phosphate and/or Sulfate.

 

Possible sources of error include:

  • Contamination of test tubes, due to improper cleaning prior to the experiment
  • Failure to keep the test tube at a 45º angle during Procedure 3.
  • Contamination of the solutions due to improperly labeled pipets, or pipet use for multiple solutions.
  • Inaccuracies in pH measurement, due to lack of litmus paper
  • Failure to follow directions
  • Human error is always in effect, given that the laboratory does not function under ideal conditions. As such, there is always the possibility of inaccuracies with measurement, perception of measurement, inaccuracies of equipment, and other such errors. (However, this is not likely to be the sole cause of the inaccuracies within this experiment, though it may contribute to it.)

Possible improvements with subsequent experiments include:

Using a larger sample size, to lessen the possibility that an anomalous result, or procedural error would disrupt the end result. Keep pipets separated. Use litmus paper. Ensure that lab partners have a functional understanding of the experiment and the reactions involved, prior to beginning the experiment.

 

During this test, our results contained significant error, due to anomalous results during procedure 2, and the premature disposal of the supernatant from Unknown Solution #2. Human error was a significant factor, though the cause of the failure within procedure 2 is unclear. Possibilities might include, contamination of the test tubes from prior experimentation, failure to keep pipets separated, which could in turn contaminate the solutions used for the test, or even the main containers from which they were taken.

Ideally, given the opportunity and time, we could repeat the test to derive a more accurate result.

DRAFT: This module has unpublished changes.