About Transcript. Boiling point elevation is the raising of a solvent’s boiling point due to the addition of a solute. Similarly, freezing point depression is the lowering of a solvent’s freezing point due to the addition of a solute. In fact, as the boiling point of a solvent increases, its freezing point decreases.

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Temperature is a measure of the average kinetic energy of the particles in matter. The Fahrenheit scale defines the freezing point of water as 32°F and the boiling point as 212°F. The Celsius scale sets the freezing point and boiling point of water at 0°C and 100°C respectively.

What are they? The boiling point is the temperature at which a material changes from a liquid to a gas (boils) while the melting point is the temperature at which a material changes from a solid to a liquid (melts). Keep in mind that a material’s melting point is the same as its freezing point.

The formula for calculating the change in freezing point is ΔTf = mKf where ΔTf is the change in the freezing point temperature, m is the molality and Kf is the freezing point constant (1.853˚C Kg/mol for water). Another colligative property change that can be made is the elevation of the boiling point.

The freezing point depression ∆T = KF·m where KF is the molal freezing point depression constant and m is the molality of the solute. Rearrangement gives: mol solute = (m) x (kg solvent) where kg of solvent is the mass of the solvent (lauric acid) in the mixture. This gives the moles of the solute.

The presence of even a small amount of impurity will lower a compound’s melting point by a few degrees and broaden the melting point temperature range. Because the impurity causes defects in the crystalline lattice, it is easier to overcome the intermolecular interactions between the molecules.

The temperature at which a solid converts itself into a liquid. The water melting point depends on the pressure above the ice (solid water) and with increasing pressure, the melting point or freezing temperature decreases.