Answer : The mass of sodium carbonate added to neutralize must be, 
Explanation :
First we have to calculate the moles of
.

Given:
Molar mass of
= 98 g/mole
Mass of
= 
Conversion used : (1 kg = 1000 g)
Now put all the given values in the above expression, we get:

The moles of
is, 
Now we have to calculate the moles of 
The balanced neutralization reaction is:

From the balanced chemical reaction we conclude that,
As, 1 mole of
neutralizes 1 mole of 
So,
of
neutralizes
Now we have to calculate the mass of 

Molar mass of
= 106 g/mole

Thus, the mass of sodium carbonate added to neutralize must be, 