Question

H1+(aq) + Fe(s) ==> H2(g) + Fe2+(aq)

I am trying to balance this equation...but I am not sure how to balance the H's.

I have the half rxns as
e- + H+(aq) ==> H2(g)
Fe(s) ==> Fe2+(aq) + 2e-

I multiplied the reduc. rxn (top) by 2 so I could get rid of the electrons...but then I am stuck on what to do with the Hydrogens and where to take it from there. Thanks!

Answer 1

You can't balance the total reaction if you don't have the half cells balanced. And your first one, with H^+, is not balanced.
e + H(aq) ==> H2(g) which becomes
2e + 2H^+ ==> H2(g) and that balances.
The second half cell balances; now you can add the redn half cell to the oxid half cell.