Why N2(g) has a lower boiling point?
than what?
Than O2?
The "old" reason had to do with a lower molar mass; the "new" reason has to do with lower intermolecular forces.
To understand why N2(g) (nitrogen gas) has a lower boiling point, we need to consider its molecular structure and intermolecular forces.
Nitrogen gas consists of diatomic molecules, meaning each molecule is composed of two nitrogen atoms bonded together. These nitrogen molecules are held together by strong triple covalent bonds within the molecule.
However, intermolecular forces are the attractive forces between different molecules. In the case of nitrogen gas, the main intermolecular force is London dispersion forces, also known as Van der Waals forces.
London dispersion forces arise due to temporary fluctuations in the electron distribution around molecules. These fluctuations generate temporary dipoles, causing neighboring molecules to be attracted to each other. The strength of London dispersion forces increases with increasing molecular size and surface area.
When a substance undergoes boiling, it transitions from a liquid to a gas phase. This transition requires breaking the intermolecular forces present in the liquid. In the case of nitrogen gas, the London dispersion forces need to be overcome to convert the gas into a liquid.
Compared to many other molecules, nitrogen gas molecules are relatively small, and thus have relatively weak intermolecular forces. This leads to a lower boiling point for nitrogen gas.
To determine the exact boiling point of nitrogen gas, you can consult a reference source, such as a chemistry textbook, handbook, or an online database. The boiling point of nitrogen gas is approximately −195.8 degrees Celsius or −320.4 degrees Fahrenheit at standard atmospheric pressure.