Which aqueous solution has a freezing point closer to its predicted value 0.01 m NaBr or 0.01 m MgCl2?

Generally, the more particles, the more deviation form ideal behavior.

To determine which aqueous solution has a freezing point closer to its predicted value, we need to understand the concept of freezing point depression and the van't Hoff factor.

Freezing point depression occurs when a solute is added to a solvent, causing the freezing point of the solution to be lower than that of the pure solvent. The extent of this depression depends on the concentration of the solute particles in the solution.

The van't Hoff factor (i) represents the number of particles a solute dissociates into when dissolved in a solvent. In other words, it indicates how many ions are produced per molecule of solute. For example, NaBr dissociates into Na+ and Br- ions, so its van't Hoff factor is 2. MgCl2 dissociates into Mg2+ and 2Cl- ions, so its van't Hoff factor is 3.

Lowering the freezing point is directly proportional to the concentration of particles in the solution. Therefore, the greater the van't Hoff factor, the more particles are present in the solution, resulting in a larger freezing point depression.

Comparing 0.01 m NaBr and 0.01 m MgCl2 solutions, we can calculate the number of particles in each solution:

0.01 m NaBr:
Number of particles = (concentration) x (van't Hoff factor) = 0.01 mol/L x 2 = 0.02 mol/L

0.01 m MgCl2:
Number of particles = (concentration) x (van't Hoff factor) = 0.01 mol/L x 3 = 0.03 mol/L

Since the concentration of particles is higher in the 0.01 m MgCl2 solution (0.03 mol/L) compared to the 0.01 m NaBr solution (0.02 mol/L), the freezing point depression will be greater in the MgCl2 solution. Therefore, the 0.01 m MgCl2 solution will have a freezing point closer to its predicted value.