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!
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.
To balance the equation, follow these steps:
1. Write down the given unbalanced equation:
H1+(aq) + Fe(s) -> H2(g) + Fe2+(aq)
2. Identify the atoms that are unbalanced. In this case, we have hydrogen (H) and iron (Fe).
3. Start by balancing the atoms other than hydrogen and oxygen. In this case, we only have iron (Fe). The equation for the reduction half-reaction shows that iron gains two electrons to form Fe2+. Therefore, we need to have two Fe atoms on the reactant side to balance the Fe2+ on the product side.
Fe -> 2Fe2+ + 2e-
4. Now, balance the oxygen atoms. In this case, we don't have any oxygen on either side of the equation.
5. Finally, balance the hydrogen atoms. Looking at the oxidation half-reaction, we have two H atoms on the reactant side (H1+). To balance the hydrogen atoms, we need to include two water molecules on the reactant side.
2H+ + 2e- -> H2
6. Now, combine the half-reactions by multiplying each half-reaction by the necessary coefficients to equalize the electrons. Multiply the reduction half-reaction by 2 to cancel out the electrons.
Fe -> 2Fe2+ + 2e-
2H+ + 2e- -> 2H2
7. Combine both half-reactions while canceling out the electrons:
2Fe + 4H+ -> 2Fe2+ + 2H2
Now the equation is balanced with respect to atoms and charge.
Keep in mind that the equation can also be simplified by dividing all coefficients by 2:
Fe + 2H+ -> Fe2+ + H2
So, the balanced equation is Fe + 2H+ -> Fe2+ + H2.