sulfuric acid(aq) mixed sodium

The reaction of mixing sulphuric acid and sodium carbonate is NOT a neutralization reaction.

The reaction of mixing sulphuric acid and sodium carbonate:
H2SO4(aq) + Na2CO3(s) --> Na2SO4(aq) + H2O(l) + CO2(g)

We do not take the ions involved into account, but we shall see that carbon dioxide is evolved after the reaction.
Since carbon dioxide ( the extra product other than water and salt ) is evolved, the reaction is not neutralization.

If you search "neutralization", you will never find the reaction which CO2 is evolved ( unless the info. is wrong ).

And accroding to wiki, neutralization is a chemical reaction where an acid and a base react to form a salt.




2011-08-06 20:28:27 補充：
If you should have any problems, ask me and I will answer you in detail.

呢個H2SO4 + Na2CO3 其實唔係neutralization

先講講點先叫做neutralization
係H+ 同OH- 或 O2- 結合成H2O
H+ + OH- --> H2O
or
2H+ + O2- --> H2O

因為Na2CO3 冇OH- 或O2-, 其實唔係neutralization

note that acid-base reaction is not necessary "neutralization" in your sense.
please consider conjugate acid/base pair:
conjugate acid of carbonate = bicarbonate, conjugate acid of bicarbonate = carbonic acid;

2011-08-07 03:34:16 補充：
conjugate base of sulfuric acid = bisulfate, conjugate base of bisulfate = sulfate.

it's still acid-base reaction, carbonic acid is just too unstable to exist.
it depends on which definition of "acid/base" you're using.

Neutralization is a chemical reaction in which an acid and a base interact with the formation of a salt to make a solution neutral.

2H+ + CO3 2- -----------------> H2O +CO2

依個都係 Neutralization.

sodium carbonate 加左水之後出NaOH

CO3 2- + H2O ----------------------> OH- + HCO3 -