Carboxylic acids and related compounds
Read our general notes on Risk Assessment
Hi. I have discovered that aspirin can undergo autocatalytic degradation to produce salicylic acid and ethanoic acid. Can you explain to me how this works as I do not completely understand this concept?
Igloo writes ...
If aspirin is allowed to come into contact with moisture, hydrolysis can take place (as it can with all esters) forming salicylic acid and ethanoic acid:
CH3COO.C6H4.COOH + H2O ----> HO.C6H4COOH + CH3COOH
Ester hydrolysis is catalysed by acid, and since both products are acids, each can effectively catalyse the very reaction which produces them. In practice this means that the hydrolysis is relatively slow to start with but accelerates as more hydrogen ions are produced.
This phenomenon is known as autocatalysis, i.e. a process in which a product causes the reaction to proceed at a faster rate without being permanently destroyed in the process.
If you wish to take this further you ought to research how acids catalyse ester hydrolysis.
Risk assessment
Before attempting any practical work based on the advice and suggestions on this website, you must do the following. Identify any hazards, assess the risks from these hazards, and then decide appropriate control measures to reduce the risks. You must have these approved by those in authority in your school or college laboratory. Do not rely on what is said on this website.
For further guidance see our tutorial on Risk Assessment.
back to Carboxylic acids and related compounds
Rate this page or react
Share your views on this page, 4 ratings so far
, rated at 
updated: 08 March 2006
