World Library  
Flag as Inappropriate
Email this Article

Volatility (chemistry)

Article Id: WHEBN0002528589
Reproduction Date:

Title: Volatility (chemistry)  
Author: World Heritage Encyclopedia
Language: English
Subject: Azeotrope, Boiling point, Lawrencium, Chemical transport reaction, Vapor pressure
Collection: Chemical Properties, Engineering Thermodynamics, Gases, Physical Chemistry, Thermodynamic Properties
Publisher: World Heritage Encyclopedia
Publication
Date:
 

Volatility (chemistry)

In chemistry and physics, volatility is the tendency of a substance to vaporize. Volatility is directly related to a substance's vapor pressure. At a given temperature, a substance with higher vapor pressure vaporizes more readily than a substance with a lower vapor pressure.[1][2][3][4]

The term is primarily written to be applied to liquids; however, it may be used to describe the process of sublimation which is associated with solid substances, such as dry ice (solid carbon dioxide) and ammonium chloride, which can change directly from the solid state to a vapor without becoming liquid.

A typical vapor pressure chart for various liquids

Contents

  • Relations between vapor pressure, temperature, and boiling point 1
  • See also 2
  • References 3
  • External links 4

Relations between vapor pressure, temperature, and boiling point

The vapor pressure of a substance is the pressure at which its gas phase is in equilibrium with its condensed phases (liquid or solid). It is a measure of the tendency of molecules and atoms to escape from a liquid or a solid. A liquid's atmospheric pressure boiling point corresponds to the temperature at which its vapor pressure is equal to the surrounding atmospheric pressure and it is often called the normal boiling point.

The higher the vapor pressure of a liquid at a given temperature, the higher the volatility and the lower the normal boiling point of the liquid. The vapor pressure chart (right hand side) displays the vapor pressures dependency for a variety of liquids as a function of temperature.[5]

For example, at any given temperature, methyl chloride has the highest vapor pressure of any of the liquids in the chart. It also has the lowest normal boiling point (−24.2 °C), which is where the vapor pressure curve of methyl chloride (the blue line) intersects the horizontal pressure line of one atmosphere (atm) of absolute vapor pressure.

See also

References

  1. ^ Gases and Vapor (University of Kentucky website)
  2. ^ Definition of Terms (University of Victoria website)
  3. ^ James G. Speight (2006). The Chemistry and Technology of Petroleum (4th Edition ed.). CRC Press.  
  4. ^ Kister, Henry Z. (1992-02-01). Distillation Design (1st Edition ed.). McGraw-hill.  
  5. ^ Perry, R.H. and Green, D.W. (Editors); Don W. Green; James O. Maloney (1997). Perry's Chemical Engineers' Handbook (7th Edition ed.). McGraw-Hill.  

External links

  • Volatility from ilpi.com
  • Definition of volatile from Wiktionary
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 


Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.