Balancing Redox Equations: Half-reaction?
Posted: Tue Jun 03, 2008 12:14 am
I am having some problem with this question, which is:
Basic solution
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) + SO3^2-(aq) → MnO2(s) + SO4^2-(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) + SO3^2-(aq) + ______ → MnO2(s) + SO4^2-(aq) + _______
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
Here is what i understand from this question:
I know that you have to make 2 half reactions which ive done:
MnO4^-(aq) → MnO2(s)
4SO3^2-(aq) → SO4^2+(aq)
From my understanding i have to add H20 to the first half reaction
MnO4^-(aq) → MnO2(s) +H2O
This is where i get confused, i don't understand if i am meant to add H+ or OH-. If it is OH- how do you balance this half equation.
Also am i right in saying you would leave the 2nd half equation as it is other then adding electrons.
Hope all that makes sense and thanks in advance.
Basic solution
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) + SO3^2-(aq) → MnO2(s) + SO4^2-(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) + SO3^2-(aq) + ______ → MnO2(s) + SO4^2-(aq) + _______
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
Here is what i understand from this question:
I know that you have to make 2 half reactions which ive done:
MnO4^-(aq) → MnO2(s)
4SO3^2-(aq) → SO4^2+(aq)
From my understanding i have to add H20 to the first half reaction
MnO4^-(aq) → MnO2(s) +H2O
This is where i get confused, i don't understand if i am meant to add H+ or OH-. If it is OH- how do you balance this half equation.
Also am i right in saying you would leave the 2nd half equation as it is other then adding electrons.
Hope all that makes sense and thanks in advance.