Question

Predict the product of reaction of ${I_2}$ with ${H_2}{O_2}$ in basic medium:
A) ${I^ - }$
B) ${I_2}{O_3}$
C) $I{O_3}^ - $
D) ${I_3}^ - $

Answer 1

Hint: When the concentration of $OH^-$ is more in the solution than it is known as basic medium. The given reaction between $I_2$ and $H_2O_2$ is occurring in the presence of $OH^-$ ions.

Complete answer:
In a basic medium when an Iodine solution reacts with Hydrogen peroxide it gives Iodide ions along with water and oxygen. Because of its instability, hydrogen peroxide easily decomposes either to water or oxygen molecules. The oxidation state of oxygen in hydrogen peroxide is - 1. It can be oxidised to oxygen or reduced to water or hydroxide ion. In aqueous solutions, hydrogen peroxide differs from the pure substance due to the effects of hydrogen bonding between water and hydrogen peroxide molecules.
The conversion of iodine to iodide is due to the oxidizing action of the hydrogen peroxide. The reaction takes place like:
${I_2} + 2OH \to 2{I^ - } + 2{H_2}O + {O_2}$
It clearly shows that when iodine is treated with hydrogen peroxide in the basic medium it gives iodide ions whereas when treated in an acidic medium it gives iodate ions.
Therefore for the aforesaid question the product of the reaction is ${I^ - }$.

Hence the correct option is option (A).

Additional Information: Hydrogen peroxide releases oxygen in the form of foam which can be used as mild antiseptic used on the skin to prevent infection of minor cuts, scrapes, and burns

Note: Hydrogen peroxide can behave either as an oxidizing agent as well as the reducing agent depending upon the medium provided for the reaction to take place. It can act in both acidic and basic medium