Here, we want to make 2N solution. So, Normality (N) = 2

Given volume = 500 mL = 0.5 L

The formula to calculate the number of moles of solute required is:

Number of moles = Normality × Volume of the solution in liters

First, calculate the number of moles of Na2CO3 required.

Number of moles = Normality × Volume of solution in liters

= 2 N × 0.5 L

= 1 mole

We need to dissolve 1 mole of Na2CO3 in 500 mL of water to make a 2N solution.

Now, calculate the mass of Na2CO3 required.

Molar mass of Na2CO3 = 106 g/mol (sodium: 2 × 23 g/mol, carbon: 1 × 12 g/mol, oxygen: 3 × 16 g/mol)

Mass = Number of moles × Molar mass

Mass = 1 mole × 106 g/mol

= 106 grams

Therefore, 106 grams of Na2CO3 need to be dissolved in 500 mL of water to make a 2N solution.