The hypothesis tested was that the percentage of copper present in a penny is around2.5% by mass based off of Congressional mandate.Various factors could affect the percentageof copper present in a penny such as the age and condition of the penny sample.Most of thecopper in a penny is present on the outer surface, so wear and tear over multiple years could leadto erosion on the surface and therefore a decrease in the % of Cu present in a penny.MethodsI.Preparation of the Standard Solutions and Penny SamplesForty milliliters of 5.00 g/L stock Cu2+solution was measured using a clean beaker.Six, 50-mL volumetric flasks were obtained and cleaned.The stock Cu2+solution, in volumes of 0.00mL, 2.00 mL, 4.00 mL, 6.00 mL, 8.00 mL, and 10.00 mL, was pipetted into the separatevolumetric flasks.