Final answer:
The option a)M Ba(NO3)2 aqueous solution has the highest boiling point because it produces the most particles upon dissociation, leading to the greatest elevation in boiling point.
Step-by-step explanation:
The aqueous solution with the highest boiling point among the given options is a) 1.25 M Ba(NO3)2. The colligative properties of solutions, such as boiling point elevation, depend on the number of solute particles in a solution. In the case of aqueous solutions of ionic compounds, the boiling point elevation is greater because the compound dissociates into ions, increasing the number of particles in the solution.
Given that Ba(NO3)2 dissociates into three ions, Ba2+ and 2NO3-, each mole of Ba(NO3)2 would produce three moles of particles contributing to boiling point elevation. Conversely, KNO3 only produces two particles per mole (K+ and NO3-), and C6H12O6 does not dissociate, providing the lowest contribution to boiling point elevation per mole.
Therefore, a 1.25 M Ba(NO3)2 solution will have a higher boiling point than the other solutions listed due to its larger number of particles after dissociation.