Pressure Cookers raise the boiling point of water. As pressure increases on a liquid, so does the boiling point. This is due to the fact that a liquid will not boil until the vapor pressure of the liquid is equals the environmental pressure surrounding the liquid. Think of it essentially as the surrounding pressure holds the substance in liquid form until it has enough energy to escape into gas form.
Pressure & Temperature :) Apex
If the ambient pressure is increased, then the boiling point temperature will rise. This is how pressure cookers operate. There are many phase diagrams for water available online. Unfortunately, link posting is not available in wikianswers at this time.
A substance can boil at a higher temperature when the external pressure is increased. This phenomenon is seen in pressure cookers, where the higher pressure raises the boiling point of water. The substance requires more energy to overcome this increased pressure and reach the higher boiling temperature.
As pressure decreases, the boiling point of water will also decrease. Backpackers camping in the high mountains are familiar with the phenomena when they get water boiling - and find that it is still only lukewarm because the atmospheric pressure at their high altitude is so low.
Different places have different elevation, and different elevations have different air pressure. It is the ambient air pressure which affects the boiling point of water. Air presses down on water, making it harder for the water to form bubbles. Less pressure produces a lower boiling point. More pressure produces a higher boiling point.
could be that this is the boiling point? so can't get hotter unless controlled in a sealed container ie steam ========== The boiling point of water is dependent on the surrounding pressure. At sea level, the expected pressure is about 1 atm and the boiling point is 100 °C. As you go up in altitude, it drops. At an elevation of around 2500 m it has dropped to a point that the water is kind of luke-warm when it boils. If you add salt or something to the water, you can elevate the boiling point a bit - even getting it up to 110 °C, but if you want to get it higher you have to keep it under pressure. That's the point of pressure cookers and pressure canning vessels. Some doctors use hydroclaves to sterilize instruments - essentially they are just pressure cookers for medical instruments.
Pressure & Temperature :) Apex
Air pressure also affects the boiling point of water. The higher the air pressure, the higher the boiling point.
boiling point increases
The relationship between pressure and the boiling point of water is that as pressure increases, the boiling point of water also increases. This means that water will boil at a higher temperature under higher pressure. Conversely, water will boil at a lower temperature under lower pressure.
If the ambient pressure is increased, then the boiling point temperature will rise. This is how pressure cookers operate. There are many phase diagrams for water available online. Unfortunately, link posting is not available in wikianswers at this time.
The boiling point of water depends on the pressure. At 1 atmosphere pressure, the boiling point is 100ºC or 212ºF.
The boiling point of water is dependent on environmental factors and the presence of solutes. In this case the pressure of the system on the water serves to increase the boiling point of water. The higher pressures increase boiling points while lowering pressure decreases it.
A substance can boil at a higher temperature when the external pressure is increased. This phenomenon is seen in pressure cookers, where the higher pressure raises the boiling point of water. The substance requires more energy to overcome this increased pressure and reach the higher boiling temperature.
When air pressure increases, the boiling point of water also increases. This is because higher air pressure pushes down on the water, making it harder for the water molecules to escape into the gas phase. As a result, more heat is needed to bring the water to its boiling point.
As pressure decreases, the boiling point of water will also decrease. Backpackers camping in the high mountains are familiar with the phenomena when they get water boiling - and find that it is still only lukewarm because the atmospheric pressure at their high altitude is so low.
Different places have different elevation, and different elevations have different air pressure. It is the ambient air pressure which affects the boiling point of water. Air presses down on water, making it harder for the water to form bubbles. Less pressure produces a lower boiling point. More pressure produces a higher boiling point.