Potassium permanganate, KMnO4, is a powerful oxidizing agent. The products of a

Question

Potassium permanganate, KMnO4, is a powerful oxidizing agent. The products of a given redox reaction with the permanganate ion depend on the reaction conditions used. In basic solution, the following equation represents the reaction of this ion with a solution containing sodium sulfite:

MnO4?(aq)+SO32?(aq)?MnO2(s)+SO42?(aq)

Since this reaction takes place in basic solution, H2O(l) and OH?(aq) will be shown in the reaction. Places for these species are indicated by the blanks in the following restatement of the equation:

MnO4?(aq)+SO32?(aq)+     ????MnO2(s)+SO42?(aq)+     ???

Part B

What are the coefficients of the six species in the balanced equation above? Remember to include H2O(l) and OH?(aq) in the blanks where appropriate.

Explanation / Answer

B.)MnO2 forms if pH=7
if pH>7 then forms MnO4(2-)
if pH=7 then:
MnO4(-)+3e+2H2O=MnO2+4OH(-) !!x2
SO3(2-)-2e+2OH(-)=SO4(2-)+H2O !!x3
============================
2MnO4(-)+4H2O+3SO3(2-)+6OH(-)=
2MnO2+8OH(-)+3SO4(2-)+3H2O
So we have:
2MnO4(-)+H2O+3SO3(2-)=
2MnO2+3SO4(2-)+2OH(-)

if pH>7 then:
MnO4(-)+e=MnO4(2-) !!x2
SO3(2-)-2e+2OH(-)=SO4(2-)+H2O
=======================
2MnO4(-)+SO3(2-)+2OH(-)=
2MnO4(2-)+SO4(2-)+H2O

Related Questions

Navigate

• Browse (All)
• Browse P
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.