Answer to Question #109098 in General Chemistry for Layla Martin

Question

at which temperature would an aqueous solution of NaCl have the lowest average kinetic energy?

Answer 1

It's a very interesting question.

Kinetic energy is the energy of the thermal motion of molecules. For gas, for example, it depends on the absolute temperature.

Accordingly, the lower the temperature, the lower the kinetic energy (including NaCl particles solvated by the liquid).

But here it must be borne in mind that water tends to freeze :)

Therefore, the lowest kinetic energy will be at the temperature of almost freezing saline.

The salt solution with the lowest melting temperature is called eutectic, and its melting temperature is called the cryohydrate point. The cryohydrate point for an ice-salt mixture with sodium chloride is -21.2 ° С, at a salt concentration in solution of 23.1% relative to the total weight of the mixture.