Question

If a substance has a heat of condensation of –1.46 kJ/g and a heat of sublimation of 4.60 kJ/g, what is its heat of solidification in kJ/g?

Answer: 1.46-4.60 kJ/g

can you explain me why the asnwer is 1.46-4.60 kJ/g

Answer 1

heat of solidification is the heat liberated by a unit mass of liquid at its freezing point as it solidifies.

Heat of sublimation is the heat required to change one mole of a substance from solid state to gaseous state at a given combination of temperature and pressure, usually standard temperature and pressure (STP).

The heat of condensation is defined as the heat released when one mole of the substance condenses at its boiling point under standard pressure.

Heat of vaporization = - heat of condensation = - (1.46) = 1.46kJ/g

Heat required from Solid to vapor = heat required from solid to liquid + heat required from liquid to vapor

Heat required from Solid to vapor = - (heat required from liquid to solid) + heat required from liquid to vapor

Heat of sublimation = - (heat of solidification) + heat of vaporization

4.60 = - (heat of solidification) + 1.46

-(Heat of solidification) = 4.60-1.46 kJ/g

Heat of solidification = - (4.60-1.46) kJ/g

Heat of solidification = 1.46 - 4.60 kJ/g