[Sleek]

Balance the Net Ionic equation for this reaction.
Cu(s) +NO3-(aq)+H+(aq) --> H2O(l)+NO2(g)+ NO3-(aq)+ Cu2+(aq)

I tried that
1Cu(s)+2NO3-(aq)+2H+(aq) --> 1H2O(l)+1NO2(g)+ 1NO3-(aq)+ 1Cu2+(aq)
but it says "some coeffcient must be '0' "

will this work?
0Cu(s)+1NO3-(aq)+2H+(aq) --> 1H2O(l)+1NO2(g)+ 0NO3-(aq)+ 0Cu2+(aq)

[Borek]

I tried that
1Cu(s)+2NO3-(aq)+2H+(aq) --> 1H2O(l)+1NO2(g)+ 1NO3-(aq)+ 1Cu2+(aq)
but it says "some coeffcient must be '0' "

Compare both sides - if the same ion is on the left and on the right, it cancels out on one side.

[Sleek]

I tried that
1Cu(s)+2NO3-(aq)+2H+(aq) --> 1H2O(l)+1NO2(g)+ 1NO3-(aq)+ 1Cu2+(aq)
but it says "some coeffcient must be '0' "

Compare both sides - if the same ion is on the left and on the right, it cancels out on one side.

what do you mean it cancels out on one side?
like this: 1Cu(s)+2NO3-(aq)+2H+(aq) --> 1H2O(l)+1NO2(g)+ 0NO3-(aq)+ 0Cu2+(aq)  ??
in the book they cross out both sides if they are the exact same.. in here only NO3- is on both sides but one side (left) has 2NO3- so it just becomes NO3- doesnt it?
also Cu is on both sides but one is solid the other is aq can they cancel out too?

[Borek]

in the book they cross out both sides if they are the exact same.. in here only NO3- is on both sides but one side (left) has 2NO3- so it just becomes NO3- doesnt it?

Yes.

also Cu is on both sides but one is solid the other is aq can they cancel out too?

Are they exactly identical?

Note: this is a redox reaction that will be easier to balance using ON or half reactions method.