Potassium Permanganate

Q. The product of oxidation of $I^{-}\text{ion by}Mn{O}_4^{-}$ in alkaline medium is

1. $I_2$
2. $I{O}_3^{-}$
3. $I_3^{-}$
4. $I{O}_4^{-}$

Q. On addition of small amount of $KMn{O}_4$ to concentrated $H_{2}S{O}_4$, a green oily compound is obtained which is highly explosive in nature. Identify the compound from the following.

1. $Mn{O}_2$
   
2. $MnS{O}_4$
   
3. $M{n}_2{O}_3$
   
4. $M{n}_2{O}_7$
   

Q. Why is $HCl$ not used to make the medium acidic in oxidation reactions of $KMn{O}_4$ in acidic medium?

1. $KMn{O}_4$ acts as a reducing agent in the presence of $HCl$
2. $KMn{O}_4$ is a weaker oxidising agent than $HCl$
3. $KMn{O}_4$ oxidises $HCl$ into $C{l}_2$ which is also an oxidising agent
4. Both $HCl$ and $KMn{O}_4$ act as oxidising agents

Q. When $KMn{O}_4$ solution is added to oxalic acid solution, the decolourisation is slow in the beginning but becomes instantaneous after some time because:

1. $C{O}_2$ is formed as the product
2. $Mn{O}_4^{-}$ catalyses the reaction
3. $M{n}^{2+}$ acts as an autocatalyst
4. The reaction is exothermic

Q. Reduction of the metal centre in aqueous permanganate ion involves

1. 3 electrons in neutral medium
2. 5 electrons in neutral medium
3. 3 electrons in alkaline medium
4. 5 electrons in acidic medium

Q. The number of moles of $KMn{O}_4$ reduced by one mole of KI in alkaline medium is

1. 1
2. 2
3. 5
4. $\frac{1}{5}$

Q. In neutral medium, $KMn{O}_4$ acts as a powerful oxidizing agent according to the reaction:
$2KMn{O}_4+H_{2}O\to 2Mn{O}_2+2KOH+3\left(O\right)$. The change involves

1. Loss of $3e^{-}$
2. Increase of $3e^{-}$
3. Loss of $5e^{-}$
4. Gain of $5e^{-}$

Q. When $Mn{O}_2$ is fused with KOH, a coloured compound is formed. The product and its colour is

1. $M{n}_2{O}_3,brown$
2. $K_{2}Mn{O}_4,green$
3. $KMn{O}_4,purple$
4. $M{n}_2{O}_4,black$

Q. In a redox reaction, how many moles of electrons are accepted by 1 mole of $Mn{O}_4$ in acidic medium?

1. 3
2. 5
3. 6
4. $\frac{5}{2}$

Q. In acidic medium if potassium permanganate is used as an oxidizing agent, we get

1. $Mn{O}_4^{2-}$
2. $M{n}^{2+}$
3. $Mn{O}_2$
4. $M{n}_2{O}_3$