Question

Reaction 6: Decomposition of Hydrogen Peroxide with Potassium Iodide 2 H2O2 (aq) + 2 I - (aq) ---> 2 H2O (l) + O2 (g) + I2 (aq) (simplified reaction) 1. Place 2 to 3 mL of hydrogen peroxide (H2O2) into a clean and dry test tube. Record observations. 2. Drop a single pellet of potassium iodide into this test tube. Over the next 2 minutes, record observations regarding any changes observed.

6

Clear solution, thicker

After drop a potassium iodide, light yellow clear solution, the solid dissolves into the solution

For Reaction 6, use your observations to come up with two clear indications that a chemical reaction occurred. Use logic to determine which one of products is orange in color. Support your answer. （Please create typed responses that are 4 to 6 sentences in length.  )Please type here for the answer.

Answer 1

The balanced chemical equation for the reaction is given. The reactants (H₂O₂ and potassium iodide, KI) are colorless while one of the products is colored. Iodine is a colored solid and the color of iodine is due to electronic transitions and interaction of light energy with the electrons. A physical reaction doesn’t change the color of the reactants. A chemical reaction produces an entirely different substance as opposed to the starting reactants (here, O₂ and I₂ are produced). In KI, the electrons behave differently than they behave in I₂; hence, I₂ is colored while KI is colorless. The appearance of color at the end of the reaction confirms that a chemical reaction has occurred indeed and I₂ is produced which is responsible for the color.