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Critical Temperature: The critical temperature of a substance is the highest temperature at which it can exist as a liquid, regardless of the pressure applied. Above this temperature, the substance cannot be liquefied by increasing the pressure, and the distinction between liquid and gas phases disappears. At the critical temperature, the properties of the liquid and vapor phases converge, leading to what is known as a supercritical fluid. For example, the critical temperature of water is 374 degrees Celsius (or 647 Kelvin) at a pressure of 22.06 MPa (about 3200 psi).
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Boiling Point and Altitude: The boiling point of a liquid is the temperature at which its vapor pressure equals the surrounding atmospheric pressure. At higher altitudes, atmospheric pressure is lower because there is less air above the surface exerting pressure. Consequently, water and other liquids reach their boiling point at lower temperatures in these conditions. For instance, at sea level (where the typical atmospheric pressure is about 101.3 kPa), the boiling point of water is 100 degrees Celsius. However, as one ascends to higher altitudes, such as in the mountains, the boiling point of water decreases. For example, at 2,500 meters (about 8,200 feet) above sea level, the boiling point of water is approximately 92 degrees Celsius. This reduction in boiling point with altitude has important implications for cooking and food preparation in mountainous regions, as food may take longer to cook due to the lower temperature of boiling water.
1.What is critical temperature
2.Explain why the boiling point depends on altitude
1 answer