In the following questions a statement of assertion (A) followed by a statement of reason (R) is given. Choose the correct option out of the choices given below each question.
Assertion (A): In the reaction between potassium permanganate and potassium iodide, permanganate ions act as oxidising agent.
Reason (R): Oxidation state of manganese changes from +2 to +7 during the reaction.
(i) Both A and R are true and R is the correct explanation of A.
(ii) Both A and R are true but R is not the correct explanation of A.
(iii) A is true but R is false.
(iv) Both A and R are false.
Option (iii) A is true but R is false.
The above shows the reaction is a redox reaction, where Mn undergoes reduction from +7 to +4 and Iodine undergoes oxidation from -1 to 0. The maximum oxidation state that Mn can reach according to electronic configuration is +7. Thus as it cannot undergo oxidation it acts as oxidising agent and itself undergoes reduction, whereas Iodine undergoes oxidation from -1 to 0.
Oxidation state of Mn changes from +7 to +4 an thus (B) is false.