In order to determine the change in boiling point, we use the formula:
ΔT = Kb * m * i
Where i is the van't Hoff factor. This factor is found by checking the number of ions formed when the solute is dissolved. This is:
Na₂SO₄ + water ↔ 2Na⁺ + SO₄⁻²
The number of ions formed is 3, so i = 3
ΔT = 0.52 * 4.5 * 3
ΔT = 7.02
The new boiling point is calculated using:
T = T(normal) + ΔT
T = 100 + 7.02
The new boiling point is 107.2 °C