Lab 9: The Synthesis and Detection of Copper

November 6, 2008 The Synthesis and Detection of Copper Julie Anne A. Day 1, Prd 4

Purpose: To transform copper (II) chloride into pure copper metal.

Materials:
-copper (II) chloride
-two medium-sized beakers
-aluminum foil
-crucible tongs
-waste container
-water
-bunsen burner


Procedure:
1. Pour 30 mL copper (II) chloride solution in the beaker.
2. Roll the aluminum foil and place it in the copper (II) chloride solution. Observe.
3. After 5 minutes, pick out the larger chunk of the aluminum foil with crucible tongs.
4. Put the solution to the waste container except for the copper at the bottom of it.
5. Put water on the copper and shake the beaker a bit.
6. Pour the water on the waste container. Then, take a piece of copper.
7. Light the Bunsen burner on to a roaring flame.
8. Do the flame test colour and burn the "made" copper. If the flame, turns green, you've made copper and your experiment is successful!

Data and Observations:

1. Copper (II) Chloride --- CuCl2

BEFORE:
It's a blue green, transparent-ish, thin liquid and it's not very viscous.
AFTER:
The same descriptions but it contained bits of black things which came off of the aluminum.
OBSERVATIONS:
Little bubbles formed when aluminum was submerged to the solution. The bubbles had an upward motion.


2. Aluminum Foil

BEFORE:
It's very shiny, smooth, metallic, easy to crumple and tear, odourless, noisy, and it seems to be ductile.
AFTER:
The part that was soaked with CuCl2 became soggy. Also, it sort of decreased in size. Furthermore, black things formed on it like barnacles on a boat. These black things increase in size and changed colour - from black to orangish brown. Also, these things looked powdery, as if they were fine grains. Finally, they fell off when the aluminum foil is shook.
OBSERVATIONS:
Bubbles formed on it and as the time passes, the bubbles became bigger and eventually, the black things formed.

3. The "Made" Copper
The copper looked soggy because it was saturated. Before it reached its orangish brownish colour, it started as black things on the aluminum foil. These black things were like barnacles on a boat when they formed on the aluminum foil. Then, they changed colour as 5 mins gone by. When the aluminum was shook, the copper fell off. When my lab partner and I burnt the copper, the flame turned green which meant we had a successful experiment.

Questions:

1. How can copper be extracted from a compound of copper, purified, and then tested to verify success.

Copper can be extracted from a compound of copper by saturating aluminum foil to that compound. The aluminum sucks the copper from the compound, copper (II) chloride, and this copper sticks to the aluminum. Another hypothesis could be that the aluminum turned to copper because as observed from the experiment, the aluminum became soggy; its pieces shortened in size; and some of the aluminum foil fell off after being saturated with copper (II) chloride.

In the BC Science 9 Book, on pg. 81, the copper was purified by putting hydrochloric acid to it. In our experiment, however, we used water because it worked as well as hydrochloric acid.

We tested the outcome of the experiment by burning it and referring to the flame test colour that we did in the earlier labs. (Basically, by flame testing.) If the flame turns green in a roaring flame, which it did for our experiment, copper is present.

Conclusion:
I learned that you can make copper just by adding/saturating aluminum foil in copper (II) chloride. I also realized that chemistry teachers may benefit from this reaction because they can use this copper made from this reaction for not-so special labs. By doing so, they don't need to buy copper for a not-so-special experiments.