Question

Identify oxidant and reductant in the following redox reactions.
$2{{K}_{2}}Mn{{O}_{4}}+C{{l}_{2}}\to 2KCl+2KMn{{O}_{4}}$

A. Oxidant: $C{{l}_{2}}$ ; Reductant: $KCl$
B. Oxidant: $C{{l}_{2}}$ ; Reductant: ${{K}_{2}}Mn{{O}_{4}}$
C. Oxidant: ${{K}_{2}}Mn{{O}_{4}}$ ; Reductant: $C{{l}_{2}}$
D. None of these

Answer 1

In chemistry, an oxidant is a substance that has the ability to oxidize other substances, the oxidant will accept the electrons and oxidises the other chemicals.

A reductant is a substance that has the ability to reduce other substances, the reductant will donate the electrons in and reduce the other chemicals.
If any chemical loses its electrons then it is called oxidation and If any chemical accepts electrons then it is called reduction .

Complete-step- by- step answer:
The given reaction is a best example for redox reaction.
In the given chemical reaction potassium manganate reacts with chlorine and forms potassium chloride and potassium permanganate.

$2{{K}_{2}}Mn{{O}_{4}}+C{{l}_{2}}\to 2KCl+2KMn{{O}_{4}}$
On left Side:
The oxidation state of Mn in ${{K}_{2}}Mn{{O}_{4}}$is ‘+6’
(x+2(1)+4(-2) = 0, then x = 6, here x = oxidation state of Manganese)
The oxidation state of chlorine in $C{{l}_{2}}$is ‘0’
On Right Side:
The oxidation state of Mn in $KMn{{O}_{4}}$is ‘+7’
The oxidation state of chlorine in $KCl$ is ‘-1’

$2{{K}_{2}}Mn{{O}_{4}}+C{{l}_{2}}\to 2KCl+2KMn{{O}_{4}}$
${+6}\;\;\;\;\;\;\;\;\;\;\;{0}\;\;\;\;\;\;\;\;{-1}\;\;\;\;\;\;\;\;\;(+7)$

$2{{K}_{2}}Mn{{O}_{4}}\to 2KMn{{O}_{4}}\to (1)$
${+6}\;\;\;\;\;\;\;\;\;\;\;\;\;\;{+7}$

$C{{l}_{2}}\to 2KCl\to (2)$
${-1}$

From the equation (1) it is clear that the oxidation state of Manganese in ${{K}_{2}}Mn{{O}_{4}}$is ‘+6’ after completion of the reaction the oxidation state of Manganese in $KMn{{O}_{4}}$is ‘+7’, means the oxidation number of manganese is increased, so ${{K}_{2}}Mn{{O}_{4}}$is a reductant.
From the equation (2) it is clear that the oxidation state of chlorine in $C{{l}_{2}}$ is ‘0’ after completion of the reaction oxidation state of chlorine in $KCl$ is ‘-1’, means oxidation state of chlorine is decreased, so, $C{{l}_{2}}$is an oxidant.
Therefore potassium manganate is a reductant and chlorine is an oxidant.

So, the correct option is B.

Note: Don’t be confused with the words oxidant and reductant.
In a redox reaction one compound loses electrons (reductant) and the other compound accepts electrons (oxidant).