08 Analytical Laboratory

This event is limited to the first 24 entries

2019 Topic: Determination of Copper in a Pennypenny

OBJECTIVE & BACKGROUND

You will determine the percent copper and the thickness of the copper layer on a penny.

According to the United States Mint, all 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.

*Except for 1943 pennies produced when all copper went to the war effort; almost all 1943 pennies were made from zinc-coated steel.


Materials Provided by NJIT on the Day of the Event:

  • Pennies
  • Benchtop spectrophotometers capable of recording the absorbance of a sample at a given wavelength
  • Test tubes to use in the spectrophotometer
  • 8.0 M nitric acid
  • Hood where the penny may be dissolved
  • Acid waste container

Materials & Methods Brought by Team to the Competition: 

  • EACH TEAM SHOULD bring whatever IS NEEDED to perform the experiment.
  • Make sure to bring 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.
  • Prior to starting, each team must provide the judges with a typed step-by-step description of the methods they intend to use 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 their experiment only if their procedure is approved by the judges in accordance with safety protocols.
  • Safety protocol must be addressed in the team's procedure submitted for evaluation prior to event.
  • Teams must practice procedure prior to event day. Judges reserve the right to dismiss unprepared teams the day of the event.


Required Activity Prior to the Event:

  1. Research, design, and execute a procedure for removing the copper from a penny.
  2. Develop a method for analyzing the copper content using a uv-vis spectrometer and standard curves.

  3. 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.

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

  5. You must practice your procedure. Judges may disqualify entrants who are not confident about their procedure, and thus pose a safety risk.  Review, be familiar with and be prepared to follow all safety guidelines associated with your chosen method.
  6. Submit step-by-step description of the methods and safety protocol and recorded tests and calculations to the NJCO Event Coordinator by the deadline indicated in the Requirement Overview (link to follow very soon!).

 

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 the school.


Time Limit:   75 minutes 


JUDGING CRITERIA

  • Description of methods, 30%
  • Description of safety concerns addressed within procedure, 10%
  • Presentation of Data and Calculations, 25%
  • Accuracy of the amount of copper in the penny, 25%
  • Time, 10%

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 they bring to this event and return them to their own schools.  

ALL PARTICIPANTS MUST BRING (APPROVED) GOGGLES, GLOVES AND 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 THEIR CHOSEN PROCEDURE.