Difference between revisions of "Nitrating mixture"

From Sciencemadness Wiki
Jump to: navigation, search
Line 10: Line 10:
  
 
==Preparation==
 
==Preparation==
Nitrating mixture is prepared by cooling a volume of concentrated sulfuric acid, usually on an ice bath. An equal volume of concentrated nitric acid is slowly added, keeping the solution at constant temperature.
+
Nitrating mixture is prepared by cooling a volume of concentrated [[sulfuric acid,]] usually on an ice bath. An equal volume of concentrated [[nitric acid]] is slowly added, keeping the solution at constant temperature. A cheaper nitrating mixture may be made by adding [[potassium nitrate]] to sulfuric acid though it may not work for some reactions.
  
 
==Safety==
 
==Safety==

Revision as of 00:01, 19 June 2015

Nitrating mixture is the name given to the mixture of concentrated nitric acid and sulfuric acid, in a 1:1 ratio, used in the nitration of organic substances. The sulfuric acid in this mixture is sufficiently strong to protonate nitric acid, producing the nitronium ion (NO2+), which is the active species in aromatic nitration.[1]

Properties

Nitrating acid is a colorless to yellow-reddish liquid, sometimes fuming reddish brown vapors (nitrogen dioxide). It is miscible with water and the dissolution releases large amounts of heat. [2]

The mixed acid solution is used in the preparation of aromatic nitrates, such as nitrobenzene, TNP, TNT, etc.

Mixed acid reacts vigorously with organic substances, generating heat and nitrogen dioxide gas.

Preparation

Nitrating mixture is prepared by cooling a volume of concentrated sulfuric acid, usually on an ice bath. An equal volume of concentrated nitric acid is slowly added, keeping the solution at constant temperature. A cheaper nitrating mixture may be made by adding potassium nitrate to sulfuric acid though it may not work for some reactions.

Safety

Mixed acid is highly corrosive and is a fire hazard. It is unstable, and should be generated in situ.

References

  1. http://en.wikipedia.org/wiki/Nitration
  2. http://cameochemicals.noaa.gov/chemical/7195

Relevant Sciencemadness threads