Question

Find out total reactions(s) with their given conditions(s), which converts \[M{n^{2 + }}\] into \[MnO_4^ - \]:
(i) \[M{n^{2 + }} + BiO_3^ - \xrightarrow{{ + {H^ \oplus }}}\] (ii) \[M{n^{2 + }} + KN{O_3} + N{a_2}C{O_3}\xrightarrow{\Delta }\]
(iii) \[Mn{O_2} + KOH + {O_2}\xrightarrow{{{\text{fused}}}}\] (iv) \[M{n^{2 + }} + Pb{O_2}\xrightarrow{{ + {H^ \oplus }}}\]
(v) \[M{n^{2 + }} + NaOH\xrightarrow{{ + air}}\] (vi) \[M{n^{2 + }} + {S_2}O_8^{2 - } + {H_2}O \to \]

Answer 1

Hint: All the above reaction are simple redox reactions. Simply perform the reaction and check the products whether \[M{n^{2 + }}\] is converted to \[MnO_4^ - \].

Complete step by step solution:
We will perform each reaction one by one and check their products.
Reaction (i):
\[M{n^{2 + }} + BiO_3^ - \xrightarrow{{ + {H^ \oplus }}}MnO_4^ - + B{i^{3 + }}\]
Reaction (ii):
\[M{n^{2 + }} + KN{O_3} + N{a_2}C{O_3}\xrightarrow{\Delta }N{a_2}Mn{O_4} + 4N{O_3} + N{a_2}S{O_4} + C{O_2}\]
Reaction (iii):
\[Mn{O_2} + KOH + {O_2}\xrightarrow{{{\text{fused}}}}{K_2}Mn{O_4} + {H_2}O\]
Reaction (iv):
\[M{n^{2 + }} + Pb{O_2}\xrightarrow{{ + {H^ \oplus }}}MnO_4^ - + P{b^{2 + }}\]
Reaction (v):
\[M{n^{2 + }} + NaOH\xrightarrow{{ + air}}Mn{(OH)_2}(s) + 2N{a^ + }\]
Reaction (vi):
\[M{n^{2 + }} + {S_2}O_8^{2 - } + {H_2}O \to MnO_4^ - + HSO_4^ - \]
Hence, we can see that only reaction (i), reaction (iv) and reaction (vi) convert \[M{n^{2 + }}\] into \[MnO_4^ - \].

Additional Information:
All these reactions redox reactions where \[M{n^{2 + }}\] is a reducing agent while other chemicals work as an oxidizing agent.
The appearance of manganese oxide is the brown-black solid or black-to-brown powder form. Potassium hydroxide has a white solid appearance. It is odorless and can be found as white or a bit yellow lumps, rods, flakes and sticks. Potassium manganate has a green appearance which gets darker and darker with time.
Lead dioxide has a dark-brown appearance and can be found as brown crystals or black or brown powder. It is insoluble in water. It has extensive uses in a positive plate of lead-acid batteries. It is also used in the production of dyes, matches and construction of high voltage arresters.
Manganese hydroxide has a white solid appearance which darkens quickly upon exposure to air due to oxidation. It is poorly soluble in water.
Peroxydisulfate, \[{S_2}O_8^{2 - }\] is a colourless, water-soluble solids that are strong oxidants. It is used in initiating the polymerization of various alkenes. It can also be used for wastewater management and the etching of copper on circuit boards.

Note:
The above reactions are not balanced since we were only checking if the required product is produced or not. When we talk about redox reaction, both oxidation and reduction are carried out in the same reaction.