New Jersey Chemistry Olympics - 2009

Event 10: Instrumentation Lab

Concentration of Colored Ionic Solutions

This event is limited to the first 24 entries

Objective

To determine the concentration of an unknown, colored, ionic solution

Materials Provided by NJIT on the Day of the Event

• 10 g sample of known sample of ionic compound (provided)
• 25 mL Unknown solution sample (provided)
• 10 x 10 graph paper (provided)

Note:  compound may be nickel II, cobalt II, iron III or copper II nitrate

Materials Brought by Team to the Competition

• Instrumentation (ex: colorimeter, Spec 20, or similar device)
• All additional materials & equipment deemed necessary by the team must be brought to the competition by the team.
• Distilled water.
• Prior to starting, each team must provide the judges with two copies of a typed step-by-step procedure for performing the reaction and isolating the product and any other the methods they intend to use to address the objective of this experiment.  Once reviewed for safety, the judges will return one copy to the students for their use.  No additional written material -- in any form -- will be permitted in this event.
• Equipment may not be shared by teams whatsoever during the competition.  

What to Do?

1. Prepare a standard solution using the sample provided by NJIT.  Prepare a set of dilutions of this standard.

2. Plot a hand drawn concentration curve using either the Spec 20, CBL, CBL-2,  LabPro or equivalent system. 10 x 10 graph paper will be supplied by NJIT.

3. Determine the concentration of the unknown in moles per liter from your graph. Show your calcualtions on the back of the report form.  

4. Clean up and then,  

5. Submit your report, along with your hand-drawn graph to the judges showing all calculations on the back of the report page.

Notes:

• Bring adequate distilled/deionized water for conducting your experiments

• At least 3 trials must be made and reported.  Show all calculations.

• All samples provided must be returned prior to leaving the room.

• Dispose of all waste products as instructed.

• The use of  unusual concentration units of solution (for example: mol/g) may aid in calculations.

Time Limit:

• 75 minutes

Judging

• Accuracy of concentration & accompanying calculations, 40%

• Description of methods, 10%

• Graph, 40%

• 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 GOGGLES (APPROVED) AND APRON OR LAB COAT, AND USE THEM AT ALL TIMES DURING THE COMPETITION. SEE NOTE ABOUT GLOVES ABOVE.

Note to Coaches:

Success in this event requires that students have a good understanding of graphing techniques.   

Event designed by Marilyn Culp, ACS-TA

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Last Updated January 04, 2009