Chemical Equation: Sulfuric acid and powdered sodium carbonate
Try to follow this reasoning. (mouse over for answer)

Which parameter is mandatory to determine if a substance precipitate or not?


   Solubility.


How does this parameter behave with sulphates?


   Many sulphates are soluble in water. Generally the sulphates become less soluble as you go down the group. So sodium sulphate is surely soluble, confirm with Wikipedia.


Additionally think about others parameters that can have some sort of influence in this to improve your understanding of chemistry. So which parameters can affect this behavior? 


   In fact as best practice you should always take in account the temperature and the amount of substance, and if the solution is saturated the excess will precipitate. 


What's the answer?


   (aq)