Chemical Equation

[cstan168]

can anyone give me a answer on what is the complete equation of:

1)Na2CO3(s)+H2O(l)-->?

and how to explain these equations(procedure run by using titration technique), is that happen impromptu?The CO2 dissolve in the aqueous?

Na2CO3(s)+HCl(aq)+H2O(l)-->NaHCO3(aq)+NaCl(aq)+H2O(l) (1)

NaHCO3(aq)+HCl(aq)+H2O(l)-->NaCl(aq)+H2CO3(aq)+H2O(l) (2)

NaCl(aq)+H2CO3(aq)+H2O(l)-->NaCl(aq)+CO3(aq)+2H2O(l) (3)

*Na2CO3(aq)+2HCl(aq)+H2O(l)-->2NaCl(aq)+CO2(aq)+H2O(l) (4)

 

is that excess of HCl titrated into the Na2CO3 when over the equilibrium point cause the second equation happen or it(2) will just happen if HCl titrated into it?