A. Questions and Observations Associated with the Procedure
1. What is the color of the crystals of CuxCly zH2O that are added to the crucible? __________________
2. Why is the heating done gently, rather than intensely (as last week)?
3. Describe what you saw during the heating as far as color goes. Does the solid all change at the same time and in the
same physical place in the sample or does it start in one area and then progress to other area(s)?
4. (i) Describe the two major changes, visually, that occurred in the beaker over the course of the first 5-10 minutes after
the wire is dropped into the solution. One of these is associated with the solution, the other with the wire.
NOTE: I do not mean the formation of bubbles here—those are not actually associated with the reaction of interest (ask, if you are interested
about the bubbles.).
(ii) What are you to assume is occurring at the molecular level to explain each of these changes?
(iii) Describe the other change (not “visual”) that occurred during the reaction, which you should have felt with your
hand during the procedure. What do you think this indicates about the reaction(s) that are occurring in the beaker
during this time?
5. After the copper is transferred to the filter paper in the Buchner funnel and washed well with water, one liquid
(ethanol, 95%) is added, allowed to sit for a bit, and then pushed through under low pressure via vacuum filtration.
Then another liquid (acetone) is used similarly, and air is drawn through via vacuum for 8 or so minutes. What is the
purpose of these steps?
