observ.html

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Here are some examples of good observations from Experiment III:

- Water in the atmosphere can affect the weight of the crucible and salt when we take it out of the dessicator to weigh it.
- Today is a pretty damp day. The humidity might make our measurements heavier!
- The drying agent in the dessicator could be saturated---the dessicator may not be completely dry.
- Although we used the watch glass on top of the beaker to reflux, a lot of volume escaped through the spout of the beaker anyway.
- When we added BaCl2, a cloudy white precipitate formed. At the same time, we saw vapors escaping from the beaker.
- When we boiled the solution again, the white precipate disappeared. It redissolved.
- When we cooled it the redissolved solution to room temperature, the white precipitate reappeared.
- When we put it into the ice bath, more precipitate formed and settled to the bottom.
- I may not have been able to get all of the precipitate out of the beaker during filtration.
- Because the precipitate is soluble in water and we washed it through the filter with water, the filtrate may contain some of our weight!!
- The salt was a large crystalline precipitate before we dried it. After drying, it looked powdery like baking soda.