The purpose of this lab was to help us understand what alloys are and how they are composed. An alloy is a mixture of a metal and one or more other elements, normally other metals. An alloy is a homogeneous mixture and is called a solution. In this lab we were to determine whether or not a coated penny was an alloy.
First we took the mass of four pennies and recorded our results. While we were doing that we were also making a sodium hydroxide solution. This made a chemical reaction, it produced heat and got up to 41 degrees Celsius, the water was originally 19 degrees Celsius. Then we heated it some more and then put the pennies in it. They turned silver, well became galvanized pennies. We took two of theses pennies to make them "gold pennies". We really just made the zinc coating a brass coating by heating it up in the Bunsen Burner. Then we weighed the pennies after we made the "gold". Our pennies seemed to loose mass. Which is kind of odd, we could have messed up weighing them in the beginning.
Although the penny was now brass, it still wasn't an alloy. If an alloy is a solution that means it is the same through out. And the penny just had a brass coating. A lot like the post 1982 pennies, they have a coating of copper over a body of zinc. If you were to try to shine your "gold penny" the gold would eventually rub off because it a very thin coating.