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Guilherme Mazui

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What is the Difference Between Normal Boiling Point and Standard Boiling Point?

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The key difference between the normal boiling point and the standard boiling point lies in the pressure at which the boiling temperature is measured.

  • Normal Boiling Point: This is the boiling temperature of a liquid at 1 atmosphere (atm) of pressure. At this pressure, the vapor pressure of the liquid becomes sufficient to overcome atmospheric pressure and allow the liquid to boil. For example, the normal boiling point of water is 99.97°C at 1 atm.
  • Standard Boiling Point: This is the boiling temperature of a liquid at 1 bar of pressure, which is slightly less than 1 atmosphere (1 bar is about 0.9967 atm). The standard boiling point has been defined by IUPAC (International Union of Pure and Applied Chemistry) since 1982. For instance, the standard boiling point of water at 1 bar is 99.61°C.

In summary:

  • The normal boiling point is the temperature at which a liquid boils at 1 atmosphere (atm) of pressure.
  • The standard boiling point is the temperature at which a liquid boils at 1 bar of pressure, as defined by IUPAC.
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  • What is the Difference Between Normal Boiling Point and Standard Boiling Point?
  • Comparative Table: Normal Boiling Point vs Standard Boiling Point

    • Comparative Table: Normal Boiling Point vs Standard Boiling Point

    The main difference between normal boiling point and standard boiling point lies in the pressure at which they are measured. Here is a comparison table highlighting the differences:

    Property Normal Boiling Point Standard Boiling Point
    Definition The boiling point of a liquid at 1 atm pressure. The boiling point of a liquid at 1 bar pressure, as defined by the IUPAC in 1982.
    Pressure 1 atm (normal or standard pressure) 1 bar (slightly lower than normal or standard pressure)
    Units Degrees Celsius (°C) or Fahrenheit (°F) Degrees Celsius (°C) or Fahrenheit (°F)
    Example The normal boiling point of water is 99.97 °C. The standard boiling point of water is 99.61 °C.

    In summary, the normal boiling point is the temperature at which a liquid boils at a pressure of 1 atm, while the standard boiling point is the temperature at which a liquid boils at a pressure of 1 bar.

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    Guilherme Mazui

    Guilherme Mazui is graduated in journalism from the Federal University of Minas Gerais (UFMG) and a master's degree in Communication from the University of São Paulo (USP). In addition, he has experience in advertising writing and has worked as a content editor in several companies.