Mixtures of oxygen and nitrogen show almost ideal boiling behaviour. Nitrogen boils at 77.36 K and oxygen boils at 90.30 K.
What is the boiling point of air?
The boiling point of air, which is a mixture of oxygen and nitrogen, can be estimated by considering the boiling behavior of its components.
Given that nitrogen boils at 77.36 K and oxygen boils at 90.30 K, we can assume that the boiling behavior of the mixture closely follows Raoult's Law for ideal solutions. According to Raoult's Law, the vapor pressure of a component in a mixture is directly proportional to the mole fraction of that component.
Since air is primarily composed of nitrogen (about 78%) and oxygen (about 21%), we can calculate the approximate mole fractions as follows:
Mole fraction of nitrogen = 0.78
Mole fraction of oxygen = 0.21
By using these values, we can estimate the boiling point of air by calculating the weighted average of the boiling points of nitrogen and oxygen:
Boiling point of air = ([Mole fraction of nitrogen] * [Boiling point of nitrogen]) + ([Mole fraction of oxygen] * [Boiling point of oxygen])
Boiling point of air = (0.78 * 77.36 K) + (0.21 * 90.30 K)
Boiling point of air = 60.33 K + 18.94 K
Boiling point of air ≈ 79.27 K
Therefore, the boiling point of air, taking into account the boiling behavior of its components, is approximately 79.27 K.