Get Penny Ante Equilibrium Lab Answers

The color change indicates that a new chemical substance has been produced. Copper on the surface of the penny has combined with oxygen in the air to produce a different substance called copper oxide.

The penny then appears to turn to gold when heated in a flame. Heat causes a fusion of zinc and copper to form brass (gold-colored). Brass is 60-82% Cu and 18-40% Zn.

Burning is an example of a chemical change. Signs of chemical change include the release of bubbles, a change of color, production of an odor, release of heat and light, and production of loud sounds.

When the silver-colored penny is heated, the outside zinc atoms and inside copper atoms move around because of the heat excitement. This makes the outer layer of zinc mix with the copper below, which becomes an alloy called yellow brass.

Increasing the concentration of a product causes the equilibrium to shift to the left, producing more reactants. Decreasing the concentration of a reactant causes the equilibrium to shift to the left, producing less products.

The silver coating on the penny is the gamma- form of the brass alloy with zinc content greater than 45%. This gives the penny its silver coloring. When the zinc-coated penny is heated, the penny becomes gold in color.

The only thing that changes an equilibrium constant is a change of temperature. The position of equilibrium may be changed if you change the pressure. ing to Le Chatelier's Principle, the position of equilibrium moves in such a way as to tend to undo the change that you have made.

Systems at equilibrium can be disturbed by changes to temperature, concentration, and, in some cases, volume and pressure; volume and pressure changes will disturb equilibrium if the number of moles of gas is different on the reactant and product sides of the reaction.

What caused the penny to turn gold? Was it a chemical or physical change? A chemical reaction between the zinc and the copper.