<u>Answer:</u> The mass of sodium carbonate reacted is 0.205 g.
<u>Explanation:</u>
To calculate the moles of a solute, we use the equation:

We are given:
Volume of nitric acid = 25 mL = 0.025 L (Conversion factor: 1 L = 1000 mL)
Molarity of the solution = 0.155 moles/ L
Putting values in above equation, we get:

For the given chemical reaction:

By Stoichiometry of the reaction:
If 2 moles of nitric acid reacts with 1 mole of sodium carbonate.
So, 0.003875 moles of nitric acid will react with
of sodium carbonate.
To calculate the mass of sodium carbonate, we use the equation:
Molar mass of sodium carbonate = 105.98 g/mol
Moles of sodium carbonate = 0.0019375 moles
Putting values in above equation, we get:

Hence, the mass of sodium carbonate reacted is 0.205 g.