Question

Define the terms ‘latent heat of vaporization’ and ‘phase change’ in your own words. What is the commonly accepted value of the latent heat of vaporization of liquid nitrogen (sometimes written LN2) in J/g? Look this up anywhere, and indicate your source of information

Answer 1

Answer:

Latent Heat of Vaporization of Nitrogen is $2.7928 KJmol^{-1}$

Explanation:

• We have learned that adding thermal energy by heat increases the temperature of a substance.

• But surprisingly, there are situations where adding energy does not change the temperature of a substance at all. Instead, the additional thermal energy acts to loosen bonds between molecules or atoms and causes a phase change.

• Because this energy enters or leaves a system during a phase change without causing a temperature change in the system, it is known as latent heat (latent means hidden).

• Latent heat of vaporization is a physical property of a substance.

• It is defined as the heat required to change one mole of liquid at its boiling point under standard atmospheric pressure. It is expressed as kg/mol or kJ/kg.

• When a material in liquid state is given energy, it changes its phase from liquid to vapor; the energy absorbed in this process is called heat of vaporization.

• Latent Heat of Vaporization of Nitrogen is $2.7928 KJmol^{-1}$