[dipndots]

I tried to balance this equation by doing the half-equations, but i only learned how to balance simple ones, and this one is not simple.



The following reaction occurs in basic solution. Balance it by adding only OH- or H2O.

MnO4-(aq) + NO2-(aq) --> MnO2(s) + NO3-(aq)

[Padfoot]

Treat as if were in an acidic environment initially.  When finished, add identical amounts of OH^- to reactants and products to remove H⁺.

[AWK]

This reaction:
MnO4-(aq) + NO2-(aq) --> MnO2(s) + NO3-(aq)
goes in neutral conditions (neutral means water on the left side (or nothing more)
MnO4-(aq) + NO2-(aq) + H2O--> MnO2(s) + NO3-(aq) + OH-

[Padfoot]

MnO4-(aq) + NO2-(aq) + H2O--> MnO2(s) + NO3-(aq) + OH-
[/quote]

AWK, this reaction doesn't seem to balance, I think it is more complex. 
Using half equations I get:

2MnO4- + 3NO2- + 5H20 → 3NO3- + 2MnO2 + 4H2O + 2OH-

Correct me if I'm wrong though.

[Borek]

Treat as if were in an acidic environment initially.  When finished, add identical amounts of OH^- to reactants and products to remove H⁺.

It works for you, which doesn't mean it is optimal.

MnO4-(aq) + NO2-(aq) + H2O--> MnO2(s) + NO3-(aq) + OH-

AWK, this reaction doesn't seem to balance, I think it is more complex. 
Using half equations I get:

2MnO4- + 3NO2- + 5H20 → 3NO3- + 2MnO2 + 4H2O + 2OH-

Correct me if I'm wrong though.

Correcting: you are wrong. This reaction can be balanced

In fact you already did it - just remove excess water.

In the future - don't hijack threads, you have stripped dipndots from a chance to do his/her homework and to learn anything.

[Padfoot]

In the future - don't hijack threads, you have stripped dipndots from a chance to do his/her homework and to learn anything.

Sorry and noted, but didn't AWK attempt to do this as well in this very thread??

[Borek]

In the future - don't hijack threads, you have stripped dipndots from a chance to do his/her homework and to learn anything.

Sorry and noted, but didn't AWK attempt to do this as well in this very thread??

I don't think so - he just hinted how to use water and OH^- to balance oxygen.

[AWK]

Sorry and noted, but didn't AWK attempt to do this as well in this very thread??

I give you direction of solving your problem (unbalanced reaction).