The boiling point of a substance is the temperature at which liquid becomes gas. It is also known as the phase change. A higher boiling point indicates a stronger intermolecular force and lower volatility.
Boiling occurs when a liquid or solution comes in contact with a hot surface. This heat can be provided by the liquid itself or by the surface. For example, a solution of acetone will have a boiling point of -138 to 530 degC.
However, there is no exact boiling point for all substances. Some substances, such as wood, don’t boil. Another important factor is the pressure that surrounds the substance. Generally, the pressure of the atmosphere will increase the boiling point.
The most important factor that affects the boiling point is the pressure in the surroundings. If the atmosphere has a low pressure, then the liquid boiling temperature will be lower. Conversely, if the atmosphere is at a high altitude, the boiling point will be higher.
The strength of intermolecular forces and the pressure surrounding the substance are the two main factors determining the boiling point. These factors depend on the mass, density and particle size of the particles. As the number of particles increases, the boiling point increases.
There are also chemical interactions between the molecules. For example, simple carboxylic acids form hydrogen bonds between molecules to dimerize. Hydrogen bonds make it harder for the molecules to leave the liquid state.
In addition to the pressure in the surrounding atmosphere, the boiling point also depends on the shape and volume of the particles. Small molecules are less dense and have more surface area than larger molecules. Therefore, the vapor pressure of smaller particles is greater than that of larger particles.