Achemist prepares two solutions: one from 28 g potassium bromide (kbr) and 1 kg water; and the other from 28 g sodium iodide (nai) and 1 kg water. what information is most useful to determine the solution that has the lower freezing point?

The information that is most useful to determine which will have a lower freezing point is the van't Hoff factor of each solute. It is the number of ions that is ionized when the solute are in solution. The higher this value, the lower is the freezing point of the solution given they have the same concentration.

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We can't until we know what we are working with or on