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Topic: Oxidation-reduction Balancing  (Read 4165 times)

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ANUABSHF

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Oxidation-reduction Balancing
« on: May 23, 2011, 05:54:27 AM »
Please help me balance this equation in both acidic and basic medium and give the specific name of the type of redox equation it is.


NO2^1- -----> NO3^1- + NO

Offline stevet

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Re: Oxidation-reduction Balancing
« Reply #1 on: May 23, 2011, 06:30:13 AM »
Firstly, can you identify the oxidation and reduction half reactions? This also might help in describing they type of redox reaction occurring.

Offline fatcat

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Re: Oxidation-reduction Balancing
« Reply #2 on: May 23, 2011, 06:49:42 PM »
Please help me balance this equation in both acidic and basic medium and give the specific name of the type of redox equation it is.


NO2^1- -----> NO3^1- + NO

First, identify half reactions, using the only reactant there for both and balancing first for major elements then the oxygens and hydrogens using H+ ions and water (H2O). Finally, you balance for the charges and add electrons to each side. Match up the number of electrons by multiplying one or both half reactions.
My finished half reactions after balancing and multiplying reduction half reaction by 3:
Reduction: 3 e- + 6 H+ + 3 NO2- ------> 3 NO- + 3 H2O
Oxidation: H2O + NO2- ----------> NO3 + 2 H+ + 3 e-


Combine both together, crossing out intermediate and catalytic reactants for finished reaction, in an acidic environment, of:
Acidic based equation: 4 NO2- + 4 H+ -----> 3 NO + NO3 + 2 H2O

But wait! You said you wanted it in basic form? Well, just add equal parts of hydroxide ions to both sides to cancel out the hydrogen ions! Voila!
Finished reaction, adding 4 OH- ions to each side:

Basic-based equation: 4 NO2- + 2 H2O -----------> 3 NO + 4 OH- + NO3

Offline stevet

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Re: Oxidation-reduction Balancing
« Reply #3 on: May 24, 2011, 05:41:37 AM »
Please help me balance this equation in both acidic and basic medium and give the specific name of the type of redox equation it is.


NO2^1- -----> NO3^1- + NO

First, identify half reactions, using the only reactant there for both and balancing first for major elements then the oxygens and hydrogens using H+ ions and water (H2O). Finally, you balance for the charges and add electrons to each side. Match up the number of electrons by multiplying one or both half reactions.
My finished half reactions after balancing and multiplying reduction half reaction by 3:
Reduction: 3 e- + 6 H+ + 3 NO2- ------> 3 NO- + 3 H2O
Oxidation: H2O + NO2- ----------> NO3 + 2 H+ + 3 e-


Combine both together, crossing out intermediate and catalytic reactants for finished reaction, in an acidic environment, of:
Acidic based equation: 4 NO2- + 4 H+ -----> 3 NO + NO3 + 2 H2O

But wait! You said you wanted it in basic form? Well, just add equal parts of hydroxide ions to both sides to cancel out the hydrogen ions! Voila!
Finished reaction, adding 4 OH- ions to each side:

Basic-based equation: 4 NO2- + 2 H2O -----------> 3 NO + 4 OH- + NO3

This answer is not correct

Offline fatcat

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Re: Oxidation-reduction Balancing
« Reply #4 on: May 24, 2011, 10:37:49 AM »
Explain? I know I accidentally put a charge on nitrogen oxide but what else?

Offline stevet

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Re: Oxidation-reduction Balancing
« Reply #5 on: May 24, 2011, 01:32:42 PM »
Yeah, its the charge on NO, and the lack of charge on NO3-. This then affects balancing electrons etc...

Also, you shouldn't give answers directly, its not how this forum would like people to answer questions.

Offline Vidya

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Re: Oxidation-reduction Balancing
« Reply #6 on: May 24, 2011, 08:14:19 PM »
Follow these steps:
identify half equations.
balance each equation separately---1. balance atoms other than H and O 2. add water to balance O 3.add H+ to balance H and in acidic medium or OH - in basic medium  4. add electrons to balance the charge

equalize number of electrons gained or lost and add both half reactions
start with these steps
you can show your working here
we will help you 

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