Kiehumiskäyrä

Kiehumiskäyrä refers to the graphical representation of a substance's boiling point at varying pressures. Typically, a kiehumiskäyrä plots temperature on the y-axis and pressure on the x-axis, illustrating the relationship between these two thermodynamic properties. As pressure increases, the boiling point of a liquid generally rises, and conversely, as pressure decreases, the boiling point lowers. This phenomenon is a direct consequence of the Clausius-Clapeyron relation, which describes the phase transition of a substance.

The kiehumiskäyrä is a fundamental concept in thermodynamics and physical chemistry, providing crucial information for processes such as distillation, evaporation, and understanding the behavior of liquids in different environments. For water, for instance, the kiehumiskäyrä shows that at standard atmospheric pressure (1 atm), it boils at 100°C. However, at higher altitudes where atmospheric pressure is lower, water boils at a temperature below 100°C. Conversely, in a pressure cooker, the increased pressure raises the boiling point of water significantly, allowing food to cook faster.

The shape and position of a kiehumiskäyrä are unique to each substance and are determined by its specific thermodynamic properties, such as its enthalpy of vaporization. These curves are essential for engineers and scientists designing and operating systems involving phase changes, ensuring safety and efficiency. They are often found in chemical engineering handbooks and scientific literature to describe the behavior of specific compounds under different conditions.