Read the detailed procedure of an experiment on your screen. Evaluate each step in the procedure to determine whether it belongs to the HOMOGENIZATION, EXTRACTION, PURIFICATION/CONCENTRATION, or ANALYSIS step.

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**Data Sheet**
**Task No. 7**
**DETERMINATION OF SULFUR CONTENT IN A SOLUBLE SULFATE SALT**

1. The sample was powdered using a mortar and pestle. This step was cautiously performed to avoid spillage and loss of the sample. The ground sample was transferred to a properly labeled container and dried for about two (2) hours in the oven at 103°C. The dried sample was then cooled and stored in a desiccator.

2. About 0.5 to 0.8 grams of the dried sample was weighed using a weighing boat and transferred to a labeled beaker. This step was repeated to make four (4) trials.

3. About 200 mL of distilled water was used to dissolve the sample, and 1 mL of concentrated HCl was added to the sample solution using a pipette. This solution was heated near boiling point using a hot plate or Bunsen burner. A 25 mL of hot barium chloride was poured gently and carefully into the hot sample solution with vigorous stirring. The precipitating agent was poured gently to reduce the Q, thereby reducing the relative supersaturation of the solution.

4. Heating the reagents near boiling point was also necessary to increase the solubility, thus reducing the relative supersaturation. Vigorous stirring would also help in breaking the electric double layer and prevent the formation of colloidal particles. The precipitate was then allowed to settle at the bottom of the beaker.

5. The supernatant liquid was tested for completeness of precipitation by adding a few more drops of hot barium chloride solution. If the supernatant liquid turns cloudy upon contact with the added drops of precipitating agent, the precipitation is not yet complete, and the hot barium chloride solution must be added until the cloudy precipitate disappears.

6. When the precipitation is complete, the beakers were covered with watch glass, and the solution was digested and kept hot (80 to 50°C) for 1 to 2 hours over a low heat setting using a hot plate.

7. After digestion, the solution was allowed to cool down. The beakers were then covered with shrink-wrap and kept in a locker until the next laboratory class schedule. This step was necessary to enhance the crystallization of the precipitate.

8. The precipitate from one beaker was collected on ashless filter paper. The beaker was rinsed thoroughly to ensure that all precipitate was transferred onto the filter paper. The same step was also done for the rest of the replicates. The precipitate was washed with hot water three times.

9. The last few drops of the filtrate were then collected into a test tube and tested for the presence of chlorides by adding 1 drop of 0.1 M AgNO₃ into the test tube. If a cloudy solution appears, the chloride is still present with the precipitate, and washing it with hot water must be repeated until the cloudy solution no longer appears.

10. The filter paper containing the precipitate was then removed from the filter funnels, folded... (The procedure seems to be incomplete here.)

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Evaluate each step according to the stage it belongs to: HOMOGENIZATION, EXTRACTION, PURIFICATION/CONCENTRATION, or ANALYSIS.