Mg (s) + HC2H3O2 (aq) --> Mg(C2H3O2)2 (aq) + H2 (g)
i balance the equation:
Mg (s) + 2HC2H3O2 (aq) --> Mg(C2H3O2)2 (aq) + H2 (g)
then i write the equation, listing all the species present in solution.
Mg (s) + 2H(+) (aq) + (C2H3O2)2(2-) (aq) --> Mg(2+) (aq)
+ (C2H3O2)2(2-) (aq) + H2 (g).
i see that (C2H3O2)2(2-) undergoes no change during the reaction. it appears on both sides of the reaction arrow and acts merely as a spectator ion, whose only role is to balance the charge. the actual reaction, when stripped to its essentials, can be described more simply by writing the following ionic equation, in which the spectator ion
(C2H3O2)2(2-) is removed:
Mg (s) + 2H(+) (aq) --> Mg(2+) (aq) + H2 (g).
leaving the spectator ion (C2H3O2)2(2-) out of the net ionic equation merely implies that the specific identity of the spectator ion is not important: any nonreactive ion could fill the same role.
is this correct?
thanks.
francisco