Question

Help me to do my lap report. Please

5. Describe the appearance of the penny in the mixture after 2 mins, and 10 mins, respectively. Post your photos. And explain how the mixture restores the original shiny brownish color. And discuss a chemical reaction that has taken place. After 2 mins After 10 mins

Please can you type the answer. Thanks

Answer 1

The metal composition of the penny is 95 percent copper and 5 percent zinc. Although copper is a shiny metal, it is also reactive. The negatively charged oxygen atoms in our air are attracted to the positively charged copper atoms in the penny. When oxygen binds with copper, they form a new molecule known as copper oxide (CuO) a black solid.

Acetic acid and NaCl (Mixture) is used to remove copper oxide without attacking the copper film, since acetic acid does not oxidize the copper surface. Acetic acid allows easy removal from a surface.

Acid in the vinegar reacts with the salt to remove copper oxide which was making your pennies dull.However the reaction takes some time occur depending on the concentration of acid and thickness of CuO layer.

After 10 min in the mixture the pennies become more shiny as compare to the 2min standing in the mixture