How can balance this complex equation?

Question

Fe + HC₂H₃O_{2 -->} Fe(C₂H₃O₂)₃ + H₂

explain steps please.

Answer 1

It's not as complicated as it looks. 

 

Notice that C₂H₃O₂ is treated as an anion (negative) and is not changed during the equation.  (In fact, it looks like an acetate ion, which means that this is the reaction when putting an iron nail into a glass of vinegar, acetic acid.)  It's the same as if it were Fe + HCl...

 

So first balance the acetates:

 

Fe + HC₂H₃O₂ --> Fe(C₂H₃O₂)₃ + H₂

Fe + 3HC₂H₃O₂ --> Fe(C₂H₃O₂)₃ + H₂

 

Now balance the H⁺ that yields the hydrogen gas.  There are 3 of those on the left, so there would have to be 1 1/2 H₂ on the right:

 

Fe + 3HC₂H₃O₂ --> Fe(C₂H₃O₂)₃ +1 1/2 H₂

 

But you can't have fractions, so multiply everything by 2 to get rid of it:

2Fe + 6HC₂H₃O₂ --> 2Fe(C₂H₃O₂)₃ + 3H₂

 

And that's it.