08 Analytical

This event is limited to the first 18 entries.

2023 Topic:  How much copper is in a penny?

Objective: determine the percent copper and the thickness of the copper layer on a pennypennies

Background: According to the US Mint, besides 1943 when all copper went to the war effort so pennies were made from zinc-coated steel, pennies have contained copper since 1793.  Pennies were made from pure copper from 1793-1837.  After that point, the amount of copper was reduced.  Today pennies are mostly made from zinc due to the high cost of copper.  The penny you will be given is made from a zinc core surrounded by a thin layer of copper.  You must determine how much copper is in your penny using spectrophotometric analysis and then determine the thickness of the copper layer.

 

Materials Provided by NJIT on the Day of the Olympics:

  • Pennies

  • Bench top spectrometers capable of recording the absorbance of a sample at a given wavelength

  • Test tubes to use in the spectrophotometer

  • 8.0 M nitric acid (read SAFETY CONSIDERATIONS BELOW!!!)

  • Hood where the penny may be dissolved

  • Acid waste container

 

Materials Brought by the Teams:

  • Bring whatever is needed to perform the experiment. Make sure to have enough deionized water.

  • Bring standard solutions of copper ions 

  • Bring appropriate glassware

  • Bring a ruler

  • Bring a graphing calculator, tablet, or computer you can use to make your standard curve

  • Safety equipment: students need to be properly protected at all times.

 

Methods:  Prior to starting, each team must provide the judges with a typed step-by-step description of the methods used to address the objective of this experiment.

 

INSTRUCTORS NOTES ON SPECIAL SAFETY CONSIDERATIONS: 

  • Laboratory should be supervised by instructor/coach at all times.

  • Review all procedures for safety concerns.

  • Teams will be permitted to perform the experiment only if the procedure is approved by the judges in accordance with safety protocols.

  • Safety protocol must be addressed in the team procedure submitted for evaluation prior to the event.

  • Teams must practice their procedure prior to event day. Judges reserve the right to dismiss unprepared teams on the day of the event.

 

Required activity Prior to the Event:

  • Research, design, and execute a procedure for removing the copper from a penny.

  • Develop a method for analyzing the copper content using a UV-vis spectrometer and standard curves.

  • Test the chosen procedure and submit the results of tests done with three different pennies.  Submit the results in a data table.  Include the characteristics of the penny (dimensions, color, condition, mint year, and location); handwritten calculations of %Cu and the thickness of the copper layer on the penny; compare your results to data from the US mint.

  • Submit step-by-step description of the methods and safety protocol and recorded tests and calculations to the Director of the NJCO by the deadline indicated in the Requirement Overview.

 

On the Day of the Event:

  • Follow the laboratory procedure designed by the team to collect and record data for a minimum of two trials.

  • Your results will be compared to known data from the US Mint

  • Clean up and take all chemicals brought to NJIT back to your school.

 

Time limit: 75 minutes.

 

Judging:

  • Description of methods

  • Description of safety concerns addressed within the procedure

  • Presentation of Data and Calculations

  • Time 

 

Notes:

  • In the event of a tie, the team that completes this session in the shortest period of time will win the tie.

  • Teams must clean up and remove all materials that are brought to this event and return them to their own schools.

 

ALL PARTICIPANTS MUST BRING (APPROVED) GOGGLES, GLOVES, AND AN APRON OR LAB COAT, AND USE THEM AT ALL TIMES DURING THE COMPETITION.  STUDENTS MUST ADHERE TO BOTH GENERAL LAB SAFETY PROTOCOLS AND THOSE SPECIFIC TO THE CHOSEN PROCEDURE