Pressure increases boiling point from "summary" of States Of Matter by A. Goel
When pressure is applied to a liquid, its boiling point increases. This is because the number of molecules in the liquid increases, resulting in a higher temperature needed to reach its boiling point. This means that liquids can be boiled at a much higher temperature than normal, depending on the pressure applied.- Pressure affects the boiling point in different ways depending on the particular type of matter. With regard to liquids, raising pressure actually raises the temperature needed for them to boil. On the other hand, when it comes to solids, increasing pressure suppresses melting. and boiling and tends to lower the temperature at which the substance would normally boil or melt.
- In order to understand why applied pressure raises boiling points, it’s helpful to look at the microscopic scale. Atoms and molecules all exert miniscule attractions on one another. The more pressure applied to a material, the stronger these attraction forces become, making it more difficult for some of the atoms to escape into the gas phase as they move faster and faster. This increase in boiling point temperature allows molecules to overcome these strong intermolecular forces.
- You may know that heat can be used to change materials, with boiling being one of the most noticeable transitions. But what is lesser known is that pressure also plays an important role in this transition. When pressure increases, boiling point increases too.
- Applying extra pressure on a material changes how it behaves physically. For example, higher pressure makes it harder for bubbles of vapor to form in liquids, which means that liquids have to become even hotter before they reach their boiling point.
- One practical example of pressure-induced boiling point increase is found in pressure cookers. By tightly sealing up a pot and introducing pressurized steam, the boiling point of water increases from around 212°F (100°C) to 250°F (121°C). Pressure cooking provides very tight control of both time and temperature, resulting in meals that are quick and cooked consistently.
