Suppose you are given a sample of a homogeneous liquid. What would you do to determine whether it is a solution or a pure substance?
There may be easier ways of doing this but I think I would place the liquid in a distilling flask fitted with a fractionating column and determine the boiling point of the compound(s).
To determine whether the given sample is a solution or a pure substance, follow these steps:
1. Observe the sample: Look at the physical appearance of the liquid. A homogeneous liquid will have a uniform composition throughout.
2. Conduct a boiling point test: Heat the liquid sample gradually and observe its boiling point. A pure substance will have a specific and constant boiling point, while a solution will undergo boiling over a range of temperatures. If the boiling point remains constant, it suggests that the liquid is a pure substance.
3. Conduct a freezing point test: Cool the liquid sample gradually and observe its freezing point. A pure substance will have a specific and constant freezing point, while a solution will undergo freezing over a range of temperatures. If the freezing point remains constant, it suggests that the liquid is a pure substance.
4. Conduct a chromatography test: Perform a chromatography test by applying the liquid sample to a chromatography paper. If only a single spot or component is observed on the paper, it suggests that the liquid is a pure substance. However, if multiple spots or components are observed, it indicates that the liquid is a solution.
5. Calculate the concentration: If you suspect that the liquid sample might be a solution, you can calculate its concentration by determining the ratio of solute to solvent. This can be done by analyzing the sample using analytical techniques such as titration or spectrophotometry.
By following these steps, you can determine whether the given sample is a solution or a pure substance.