Combining Iodine and Zinc

2.7 based on 6 ratings

Updated on Dec 09, 2011

Grade Level: 9th to 10th; Type: Chemistry


In this experiment you will be making a compound of different elements by taking iodine and zinc and combining them to make zinc iodide.

Research Questions:

  • If you add the mass of zinc and iodine together, how would it relate to the zinc iodide compound?
  • Do your results prove or disprove the Law of Conservation of Mass?
  • How are the original elements different from the compound produced in this experiment? i.e. color, shape, etc.


  • Granular zinc (10 – 50) mesh
  • Iodine crystals
  • Hot hands gripping pad
  • Vinegar (0.9M acetic acid)
  • Weighing dishes
  • Hot plate
  • Stir rod
  • Copper (platinum) electrodes
  • 50mL Erlenmeyer flask
  • 125mL Erlenmeyer flask
  • 10mL Graduated cylinder
  • Electronic balance
  • Scoops (Spatulas)
  • Petri Dish
  • 9 V battery
  • Alligator leads (2)

Experimental Procedure

  1. Add 2g of iodine, followed by 2g of granular zinc to the 50mL flask.
  2. Add 5mL of vinegar and swirl. Wait for the color to stop changing and result to a clear liquid.
  3. You should now only have zinc and liquid in your Erlenmeyer flask.
  4. Place the liquids into a 125mL flask while leaving the solid zinc in the 50mL flask.
  5. Rinse the remaining zinc with 1mL of vinegar three times. Add the rinses to the 125mL flask.
  6. What you have now in the 125mL flask, is a zinc iodide solution. Heat this solution on the hot plate with a low setting. The solid zinc iodide will come out of the solution as the water is boiled away. You are done when the zinc iodide turns an off-white or light yellow color. Do NOT let it turn dark yellow or orange. This is indicating that it has started to decompose because it is being heated too strongly.
  7. You should now have solid zinc iodide. Congratulations, you have made a compound!

Terms/Concepts: compounds, elements, isolating, mixtures, solutions, decomposition


Elements and compounds:

Chemical decomposition:

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