Chemistry of Coppers

The Chemistry of Coppers

1. Introduction

2. Aim of the Experiment

3. Safety Requirements

4. Materials List

5. Method

6. Results

7. Experimental Errors

8. Conclusion

9. References

1. Introduction

Copper (Cu) is located in group 11, period 4, and is a transition metal with an atomic number of 29. Copper has been used for thousands of years, either used as a monetary unit, or made used in alloys. Household methods of cleaning copper are by using Acetic Acid, or in simple terms, household vinegar. Copper, in its natural state, is the most stable form, Cu-63. Although Cu is the least reactive metal in the series, it slowly reacts with atmospheric oxygen, and in time it is oxidised and forms Copper II Oxide (Cu2O ). Oxidation is the process when an element loses electrons and/or hydrogen on reacting with another element. This reaction can be increased by heating copper over a flame, and we notice that the copper becomes oxidised. In my experiment, I will show how copper is oxidised by atmospheric oxygen with the help of heating it, causing it to form Copper II Oxide, and how the oxidative layer is reduced by vinegar, Acetic Acid (Ch3COOH). After the wires have been cleaned, I will rinse one piece with water, and let the other piece to dry. The un-rinsed piece of copper will promote a reaction and it will form Copper Carbonate (CuCO3).(Penny Reactions, Article 1)

2. Aims of the Experiment

Since copper reacts very slowly with atmospheric oxygen, we will observe what happens when we put two piece of copper wire under a flame and then how the oxidative layer of CuO forms on the outside. After the oxidative layer (CuO) is formed on the outside, we will then take vinegar, add table salt to it, to form a very weak solution of hydrochloric acid (HCl) and observe how acetic acid reacts with the oxidative layer, and forms copper acetate [Cu(CH3COO)2]. The copper acetate is water soluble, dissolving away and it should leave a clear shiny copper metal surface. After we rinse one sample, and dry it, and take the other sample, and leave it without rinsing it, we will see that a reaction will occur again after a while, which will form Copper Carbonate (CuCO3)

3. Safety Requirements

This experiment requires that great care be taken when handling the copper and heating it over the flame, and for this purpose, mittens should be worn. The end product, which is copper acetate, should be disposed of properly and should be handled with extreme care. It causes irritation to the respiratory system, eyes, skin and if swallowed if can cause copper poisoning. To avoid all this, this experiment should be done in a well-ventilated place, gloves, lab coat, and eye goggles should be worn. Copper acetate is VERY harmful to aquatic life, it should be disposed properly. (MSDS-Copper Acetate, p 1)

4. Materials List

* 2x Copper Wire 4 in

* Pliers

* Vinegar (Acetic Acid) 250ml

* Deep container

* Source of heat (e.g. stove flame)

* Hot mat * Gloves

* Lab