Question

For freezing point depression what are 2 reasonable explanations for error? what will happen if it gets low value? what will happen if it gets high value? what advice would you give to someone about ice bath or freezing process ?

Answer 1

Freezing point depression is a colligative property of solutions. Solutions freezing points are lower than that of the pure solvent or solute because freezing, or becoming solid, creates order and decreases entropy. Solutions have high entropy because of the mix of solvent and solute, so it takes more energy to decrease their entropy to the same point.

Aqueous solutions have both a lower freezing point and a higher boiling point than pure water. Probably one of the most familiar applications of this phenomenon is the addition of ethylene glycol (“antifreeze”) to the water in an automobile radiator. This solute lowers the freezing point of the water, preventing the engine from cracking in very cold weather from the expansion of pure water on freezing.

At higher concentrations, especially with salts of small, highly charged ions , or in solutions with less polar solvents, dissociation to give separate ions is often incomplete. The sum of the concentrations of the dissolved solute particles dictates the physical properties of a solution. In the following discussion, we must therefore keep the chemical nature of the solute firmly in mind.