Chapter 2, Problem 1Q

Interpretation Introduction

Interpretation:

The balanced chemical reaction between iodide ion, peroxide and hydrogen ion is to be written. Also, the change in color should be explained.

Concept introduction:

Peroxides are organic molecules that are sensitive to heat and are represented as $\left(\text{R}-\text{O}-\text{O}-\text{R}\right)$. The compounds which react in presence of oxygen and light and form peroxides are ethers, alcohols, aldehydes, alkenes, and other cyclic compounds. Peroxide undergoes oxidation and forms water and iodine gas when reacts with hydrogen ion and iodide ion.

Answer to Problem 1Q

The product of the reaction between hydrogen ion, peroxide and iodide ion is water and iodine gas.

The balanced reaction is as given below,

  $\text{ROOR}+2{\text{I}}^{-}+2{\text{H}}^{+}\to 2\text{ROH}+{\text{I}}_{\text{2}}\uparrow$

The color of the formed product varies with the concentration of peroxide in the substrate. If the concentration is high the color is brown while low concentration gives a yellow color.

Explanation of Solution

The reaction between iodide ion, peroxide and hydrogen ion reacts to form water and iodine gas as a product. The reaction can be given as,

  $\text{ROOR}+{\text{I}}^{-}+{\text{H}}^{+}\to \text{ROH}+{\text{I}}_{\text{2}}\uparrow$

To balance the equation place a coefficient 2 in front of $\text{ROH}$ , iodide ion and hydrogen ion. The balanced chemical equation is,

  $\text{ROOR}+2{\text{I}}^{-}+2{\text{H}}^{+}\to 2\text{ROH}+{\text{I}}_{\text{2}}\uparrow$

The yellow color is of iodine gas. The concentration of the peroxide in the substrate decides the color of the product formed. If the concentration of peroxide is less the color is yellow while higher concentration leads to brown color.

Conclusion

Thus, the product of the reaction between hydrogen ion, peroxide and iodide ion is iodine gas and the color depends on the concentration of peroxide in the substrate.